Science.gov

Sample records for acinar cell death

  1. The course and nature of acinar cell death following pancreatic ligation in the guinea pig.

    PubMed Central

    Zeligs, J. D.; Janoff, A.; Dumont, A. E.

    1975-01-01

    The course and nature of acinar cell death (ACD) following pancreatic ligation in the guinea pig was studied as a possible model for human disease. Ultrastructural studies after various periods of ligation suggested a biphasic pattern of ACD. Early phase ACD involved only a small portion of acinar cells and occurred within a few hours of ligation. It was preceded by swelling and vesiculation of the rough endoplasmic reticulum. Morphometric measurements disclosed celular swelling at this time, and NaCl equilibration studies demonstrated a change in cellular osmoregulation. Late phase ACD, characterized by cellular wasting and autophagic vacuole formation, became prominent several days after ligation. Marked increases in lysosomal enzyme activities were found in tissue homogenates at this time, and acid phosphatase electron histochemistry localized the majority of this increased activity to lysosomes and autophagic vacuoles within the acinar cells. The etiology and nature of both phases of ACD are discussed. Images Figure 5 Figure 6 Figure 12 Figure 7 Figure 8 Figure 1 Figure 2 Figure 9 Figure 10 Figure 11 Figure 3 Figure 4 PMID:169698

  2. Pancreatic acinar cells produce, release, and respond to tumor necrosis factor-alpha. Role in regulating cell death and pancreatitis.

    PubMed Central

    Gukovskaya, A S; Gukovsky, I; Zaninovic, V; Song, M; Sandoval, D; Gukovsky, S; Pandol, S J

    1997-01-01

    The aim of this study was to determine whether tumor necrosis factor-alpha (TNFalpha) and receptors for TNFalpha are expressed in the exocrine pancreas, and whether pancreatic acinar cells release and respond to TNFalpha. Reverse transcription PCR, immunoprecipitation, and Western blot analysis demonstrated the presence of TNFalpha and 55- and 75-kD TNFalpha receptors in pancreas from control rats, rats with experimental pancreatitis induced by supramaximal doses of cerulein, and in isolated pancreatic acini. Immunohistochemistry showed TNFalpha presence in pancreatic acinar cells. ELISA and bioassay measurements of TNFalpha indicated its release from pancreatic acinar cells during incubation in primary culture. Acinar cells responded to TNFalpha. TNFalpha potentiated NF-kappaB translocation into the nucleus and stimulated apoptosis in isolated acini while not affecting LDH release. In vivo studies demonstrated that neutralization of TNFalpha with an antibody produced a mild improvement in the parameters of cerulein-induced pancreatitis. However, TNFalpha neutralization greatly inhibited apoptosis in a modification of the cerulein model of pancreatitis which is associated with a high percentage of apoptotic cell death. The results indicate that pancreatic acinar cells produce, release, and respond to TNFalpha. This cytokine regulates apoptosis in both isolated pancreatic acini and experimental pancreatitis. PMID:9312187

  3. Therapeutic potential of targeting acinar cell reprogramming in pancreatic cancer.

    PubMed

    Wong, Chi-Hin; Li, You-Jia; Chen, Yang-Chao

    2016-08-21

    Pancreatic ductal adenocarcinoma (PDAC) is a common pancreatic cancer and the fourth leading cause of cancer death in the United States. Treating this life-threatening disease remains challenging due to the lack of effective prognosis, diagnosis and therapy. Apart from pancreatic duct cells, acinar cells may also be the origin of PDAC. During pancreatitis or combined with activating KRas(G12D) mutation, acinar cells lose their cellular identity and undergo a transdifferentiation process called acinar-to-ductal-metaplasia (ADM), forming duct cells which may then transform into pancreatic intraepithelial neoplasia (PanIN) and eventually PDAC. During ADM, the activation of mitogen-activated protein kinases, Wnt, Notch and phosphatidylinositide 3-kinases/Akt signaling inhibits the transcription of acinar-specific genes, including Mist and amylase, but promotes the expression of ductal genes, such as cytokeratin-19. Inhibition of this transdifferentiation process hinders the development of PanIN and PDAC. In addition, the transdifferentiated cells regain acinar identity, indicating ADM may be a reversible process. This provides a new therapeutic direction in treating PDAC through cancer reprogramming. Many studies have already demonstrated the success of switching PanIN/PDAC back to normal cells through the use of PD325901, the expression of E47, and the knockdown of Dickkopf-3. In this review, we discuss the signaling pathways involved in ADM and the therapeutic potential of targeting reprogramming in order to treat PDAC. PMID:27610015

  4. Therapeutic potential of targeting acinar cell reprogramming in pancreatic cancer

    PubMed Central

    Wong, Chi-Hin; Li, You-Jia; Chen, Yang-Chao

    2016-01-01

    Pancreatic ductal adenocarcinoma (PDAC) is a common pancreatic cancer and the fourth leading cause of cancer death in the United States. Treating this life-threatening disease remains challenging due to the lack of effective prognosis, diagnosis and therapy. Apart from pancreatic duct cells, acinar cells may also be the origin of PDAC. During pancreatitis or combined with activating KRasG12D mutation, acinar cells lose their cellular identity and undergo a transdifferentiation process called acinar-to-ductal-metaplasia (ADM), forming duct cells which may then transform into pancreatic intraepithelial neoplasia (PanIN) and eventually PDAC. During ADM, the activation of mitogen-activated protein kinases, Wnt, Notch and phosphatidylinositide 3-kinases/Akt signaling inhibits the transcription of acinar-specific genes, including Mist and amylase, but promotes the expression of ductal genes, such as cytokeratin-19. Inhibition of this transdifferentiation process hinders the development of PanIN and PDAC. In addition, the transdifferentiated cells regain acinar identity, indicating ADM may be a reversible process. This provides a new therapeutic direction in treating PDAC through cancer reprogramming. Many studies have already demonstrated the success of switching PanIN/PDAC back to normal cells through the use of PD325901, the expression of E47, and the knockdown of Dickkopf-3. In this review, we discuss the signaling pathways involved in ADM and the therapeutic potential of targeting reprogramming in order to treat PDAC.

  5. Therapeutic potential of targeting acinar cell reprogramming in pancreatic cancer

    PubMed Central

    Wong, Chi-Hin; Li, You-Jia; Chen, Yang-Chao

    2016-01-01

    Pancreatic ductal adenocarcinoma (PDAC) is a common pancreatic cancer and the fourth leading cause of cancer death in the United States. Treating this life-threatening disease remains challenging due to the lack of effective prognosis, diagnosis and therapy. Apart from pancreatic duct cells, acinar cells may also be the origin of PDAC. During pancreatitis or combined with activating KRasG12D mutation, acinar cells lose their cellular identity and undergo a transdifferentiation process called acinar-to-ductal-metaplasia (ADM), forming duct cells which may then transform into pancreatic intraepithelial neoplasia (PanIN) and eventually PDAC. During ADM, the activation of mitogen-activated protein kinases, Wnt, Notch and phosphatidylinositide 3-kinases/Akt signaling inhibits the transcription of acinar-specific genes, including Mist and amylase, but promotes the expression of ductal genes, such as cytokeratin-19. Inhibition of this transdifferentiation process hinders the development of PanIN and PDAC. In addition, the transdifferentiated cells regain acinar identity, indicating ADM may be a reversible process. This provides a new therapeutic direction in treating PDAC through cancer reprogramming. Many studies have already demonstrated the success of switching PanIN/PDAC back to normal cells through the use of PD325901, the expression of E47, and the knockdown of Dickkopf-3. In this review, we discuss the signaling pathways involved in ADM and the therapeutic potential of targeting reprogramming in order to treat PDAC. PMID:27610015

  6. Loss of acinar cell IKKα triggers spontaneous pancreatitis in mice

    PubMed Central

    Li, Ning; Wu, Xuefeng; Holzer, Ryan G.; Lee, Jun-Hee; Todoric, Jelena; Park, Eek-Joong; Ogata, Hisanobu; Gukovskaya, Anna S.; Gukovsky, Ilya; Pizzo, Donald P.; VandenBerg, Scott; Tarin, David; Atay, Çiǧdem; Arkan, Melek C.; Deerinck, Thomas J.; Moscat, Jorge; Diaz-Meco, Maria; Dawson, David; Erkan, Mert; Kleeff, Jörg; Karin, Michael

    2013-01-01

    Chronic pancreatitis is an inflammatory disease that causes progressive destruction of pancreatic acinar cells and, ultimately, loss of pancreatic function. We investigated the role of IκB kinase α (IKKα) in pancreatic homeostasis. Pancreas-specific ablation of IKKα (IkkαΔpan) caused spontaneous and progressive acinar cell vacuolization and death, interstitial fibrosis, inflammation, and circulatory release of pancreatic enzymes, clinical signs resembling those of human chronic pancreatitis. Loss of pancreatic IKKα causes defective autophagic protein degradation, leading to accumulation of p62-mediated protein aggregates and enhanced oxidative and ER stress in acinar cells, but none of these effects is related to NF-κB. Pancreas-specific p62 ablation prevented ER and oxidative stresses and attenuated pancreatitis in IkkαΔpan mice, suggesting that cellular stress induced by p62 aggregates promotes development of pancreatitis. Importantly, downregulation of IKKα and accumulation of p62 aggregates were also observed in chronic human pancreatitis. Our studies demonstrate that IKKα, which may control autophagic protein degradation through its interaction with ATG16L2, plays a critical role in maintaining pancreatic acinar cell homeostasis, whose dysregulation promotes pancreatitis through p62 aggregate accumulation. PMID:23563314

  7. PD2/Paf1 depletion in pancreatic acinar cells promotes acinar-to-ductal metaplasia

    PubMed Central

    Dey, Parama; Rachagani, Satyanarayana; Vaz, Arokia P.; Ponnusamy, Moorthy P.; Batra, Surinder K.

    2014-01-01

    Pancreatic differentiation 2 (PD2), a PAF (RNA Polymerase II Associated Factor) complex subunit, is overexpressed in pancreatic cancer cells and has demonstrated potential oncogenic property. Here, we report that PD2/Paf1 expression was restricted to acinar cells in the normal murine pancreas, but its expression increased in the ductal cells of Pdx1Cre; KrasG12D (KC) mouse model of pancreatic cancer with increasing age, showing highest expression in neoplastic ductal cells of 50 weeks old mice. PD2/Paf1 was specifically expressed in amylase and CK19 double positive metaplastic ducts, representing intermediate structures during pancreatic acinar-to-ductal metaplasia (ADM). Similar PD2/Paf1 expression was observed in murine pancreas that exhibited ADM-like histology upon cerulein challenge. In normal mice, cerulein-mediated inflammation induced a decrease in PD2/Paf1 expression, which was later restored upon recovery of the pancreatic parenchyma. In KC mice, however, PD2/Paf1 mRNA level continued to decrease with progressive dysplasia and subsequent neoplastic transformation. Additionally, knockdown of PD2/Paf1 in pancreatic acinar cells resulted in the abrogation of Amylase, Elastase and Lipase (acinar marker) mRNA levels with simultaneous increase in CK19 and CAII (ductal marker) transcripts. In conclusion, our studies indicate loss of PD2/Paf1 expression during acinar transdifferentiation in pancreatic cancer initiation and PD2/Paf1 mediated regulation of lineage specific markers. PMID:24947474

  8. Pancreatic acinar cells-derived cyclophilin A promotes pancreatic damage by activating NF-κB pathway in experimental pancreatitis

    SciTech Connect

    Yu, Ge; Wan, Rong; Hu, Yanling; Ni, Jianbo; Yin, Guojian; Xing, Miao; Shen, Jie; Tang, Maochun; Chen, Congying; Fan, Yuting; Xiao, Wenqin; Zhao, Yan; Wang, Xingpeng; and others

    2014-01-31

    Highlights: • CypA is upregulated in experimental pancreatitis. • CCK induces expression and release of CypA in acinar cell in vitro. • rCypA aggravates CCK-induced acinar cell death and inflammatory cytokine production. • rCypA activates the NF-κB pathway in acinar cells in vitro. - Abstract: Inflammation triggered by necrotic acinar cells contributes to the pathophysiology of acute pancreatitis (AP), but its precise mechanism remains unclear. Recent studies have shown that Cyclophilin A (CypA) released from necrotic cells is involved in the pathogenesis of several inflammatory diseases. We therefore investigated the role of CypA in experimental AP induced by administration of sodium taurocholate (STC). CypA was markedly upregulated and widely expressed in disrupted acinar cells, infiltrated inflammatory cells, and tubular complexes. In vitro, it was released from damaged acinar cells by cholecystokinin (CCK) induction. rCypA (recombinant CypA) aggravated CCK-induced acinar cell necrosis, promoted nuclear factor (NF)-κB p65 activation, and increased cytokine production. In conclusion, CypA promotes pancreatic damage by upregulating expression of inflammatory cytokines of acinar cells via the NF-κB pathway.

  9. TGF-β1 promotes acinar to ductal metaplasia of human pancreatic acinar cells

    PubMed Central

    Liu, Jun; Akanuma, Naoki; Liu, Chengyang; Naji, Ali; Halff, Glenn A.; Washburn, William K.; Sun, Luzhe; Wang, Pei

    2016-01-01

    Animal studies suggest that pancreatitis-induced acinar-to-ductal metaplasia (ADM) is a key event for pancreatic ductal adenocarcinoma (PDAC) initiation. However, there has not been an adequate system to explore the mechanisms of human ADM induction. We have developed a flow cytometry-based, high resolution lineage tracing method and 3D culture system to analyse ADM in human cells. In this system, well-known mouse ADM inducers did not promote ADM in human cells. In contrast, TGF-β1 efficiently converted human acinar cells to duct-like cells (AD) in a SMAD-dependent manner, highlighting fundamental differences between the species. Functionally, AD cells gained transient proliferative capacity. Furthermore, oncogenic KRAS did not induce acinar cell proliferation, but did sustain the proliferation of AD cells, suggesting that oncogenic KRAS requires ADM-associated-changes to promote PDAC initiation. This ADM model provides a novel platform to explore the mechanisms involved in the development of human pancreatic diseases. PMID:27485764

  10. Fibronectin Expression Modulates Mammary Epithelial Cell Proliferation during Acinar Differentiation

    PubMed Central

    Williams, Courtney M.; Engler, Adam J.; Slone, R. Daniel; Galante, Leontine L.; Schwarzbauer, Jean E.

    2009-01-01

    The mammary gland consists of a polarized epithelium surrounded by a basement membrane matrix that forms a series of branching ducts ending in hollow, sphere-like acini. Essential roles for the epithelial basement membrane during acinar differentiation, in particular laminin and its integrin receptors, have been identified using mammary epithelial cells cultured on a reconstituted basement membrane. Contributions from fibronectin, which is abundant in the mammary gland during development and tumorigenesis, have not been fully examined. Here, we show that fibronectin expression by mammary epithelial cells is dynamically regulated during the morphogenic process. Experiments with synthetic polyacrylamide gel substrates implicate both specific extracellular matrix components, including fibronectin itself, and matrix rigidity in this regulation. Alterations in fibronectin levels perturbed acinar organization. During acinar development, increased fibronectin levels resulted in overproliferation of mammary epithelial cells and increased acinar size. Addition of fibronectin to differentiated acini stimulated proliferation and reversed growth arrest of mammary epithelial cells negatively affecting maintenance of proper acinar morphology. These results show that expression of fibronectin creates a permissive environment for cell growth that antagonizes the differentiation signals from the basement membrane. These effects suggest a link between fibronectin expression and epithelial cell growth during development and oncogenesis in the mammary gland. PMID:18451144

  11. Effects of Benzodiazepines on Acinar and Myoepithelial Cells

    PubMed Central

    Mattioli, Tatiana M. F.; Alanis, Luciana R. A.; Sapelli, Silvana da Silva; de Lima, Antonio A. S.; de Noronha, Lucia; Rosa, Edvaldo A. R.; Althobaiti, Yusuf S.; Almalki, Atiah H.; Sari, Youssef; Ignacio, Sergio A.; Johann, Aline C. B. R.; Gregio, Ana M. T.

    2016-01-01

    Background: Benzodiazepines (BZDs), the most commonly prescribed psychotropic drugs with anxiolytic action, may cause hyposalivation. It has been previously shown that BZDs can cause hypertrophy and decrease the acini cell number. In this study, we investigated the effects of BZDs and pilocarpine on rat parotid glands, specifically on acinar, ductal, and myoepithelial cells. Methods: Ninety male Wistar rats were divided into nine groups. Control groups received a saline solution for 30 days (C30) and 60 days (C60), and pilocarpine (PILO) for 60 days. Experimental groups received lorazepam (L30) and midazolam (M30) for 30 days. Another group (LS60 or MS60) received lorazepam or midazolam for 30 days, respectively, and saline for additional 30 days. Finally, other groups (LP60 or MP60) received either lorazepam or midazolam for 30 days, respectively, and pilocarpine for additional 30 days. The expression of calponin in myoepithelial cells and the proliferating cell nuclear antigen (PCNA) in acinar and ductal cells were evaluated. Results: Animals treated with lorazepam showed an increase in the number of positive staining cells for calponin as compared to control animals (p < 0.05). Midazolam administered with pilocarpine (MP60) induced an increase in the proliferation of acinar and ductal cells and a decrease in the positive staining cells for calponin as compared to midazolam administered with saline (MS60). Conclusion: We found that myoepithelial cells might be more sensitive to the effects of BZD than acinar and ductal cells in rat parotid glands. PMID:27445812

  12. Root bark extracts of Juncus effusus and Paeonia suffruticosa protect salivary gland acinar cells from apoptotic cell death induced by cis-platinum (II) diammine dichloride.

    PubMed

    Mukudai, Yoshiki; Kondo, Seiji; Shiogama, Sunao; Koyama, Tomoyuki; Li, Chunnan; Yazawa, Kazunaga; Shintani, Satoru

    2013-12-01

    Cis-platinum (II) diammine dichloride (CDDP) is a platinum-based anticancer agent, and is often used for chemotherapy for malignant tumors, albeit CDDP has serious side-effects, including xerostomia (dry mouth). Since patients with xerostomia have reduced quality of life, it is urgent and important to identify nontoxic and natural agents capable of reducing the adverse effect of chemotherapy on salivary gland function. Therefore, we commenced an institutional collaborative project in which candidates of herbal extracts were selected from more than 400 bioactive herbal products for their potential therapeutic effects not only on xerostomia, but also on oral diseases. In the present study, we report on two Chinese medical herbal extracts from the root barks of Juncus effusus and Paeonia suffruticosa. The two extracts showed a protective effect in NS-SV-Ac cells from the cytotoxicity and apoptosis caused by CDDP. The effect was dependent on the p53 pathway, protein kinase B/Akt 1 and mitochondrial apoptosis-related proteins (i.e. Bcl-2 and Bax), but was not dependent on nuclear factor κB. Notably, the apoptosis-protective effect of the extracts was not observed in adenocystic carcinoma cell lines. Although these extracts have been utilized in traditional Chinese medicine for hundreds of years, there are no reports to our knowledge, on their therapeutic effects on xerostomia. Thus, in the present study, we elucidated the potency of these herbal extracts as novel candidates for xerostomia to improve the quality of life of patients undergoing chemotherapy.

  13. Regulation of Acinar Cell Function in The Pancreas

    PubMed Central

    Williams, John A.

    2011-01-01

    Purpose of Review This review identifies and puts into context the recent articles which have advanced understanding of the functions of pancreatic acinar cells and the mechanisms by which these functions are regulated. Recent Findings Receptors present on acinar cells, particularly those for cholecystokinin and secretin, have been better characterized as to the molecular nature of the ligand-receptor interaction. Other reports have described the potential regulation of acinar cells by GLP-1 and cannabinoids. Intracellular Ca2+ signaling remains at the center of stimulus secretion coupling and its regulation has been further defined. Recent studies have identified specific channels mediating Ca2+ release from intracellular stores and influx across the plasma membrane.Work downstream of intracellular mediators has focused on molecular mechanisms of exocytosis particularly involving small G proteins, SNARE proteins and chaperone molecules. In addition to secretion, recent studies have further defined the regulation of pancreatic growth both in adaptive regulation to diet and hormones in the regeneration that occurs after pancreatic damage. Lineage tracing has been used to show the contribution of different cell types. The importance of specific amino acids as signaling molecules to activate the mTOR pathway is being elucidated. Summary Understanding the mechanisms that regulate pancreatic acinar cell function is contributing to knowledge of normal pancreatic function and alterations in disease. PMID:20625287

  14. Characterization of cysteine string protein in rat parotid acinar cells.

    PubMed

    Shimomura, Hiromi; Imai, Akane; Nashida, Tomoko

    2013-10-01

    Cysteine string proteins (CSPs) are secretory vesicle chaperone proteins that contain: (i) a heavily palmitoylated cysteine string (comprised of 14 cysteine residues, responsible for the localization of CSP to secretory vesicle membranes), (ii) an N-terminal J-domain (DnaJ domain of Hsc70, 70kDa heat-shock cognate protein family of co-chaperones), and (iii) a linker domain (important in mediating CSP effects on secretion). In this study, we investigated the localization of CSP1 in rat parotid acinar cells and evaluated the role of CSP1 in parotid secretion. RT-PCR and western blotting revealed that CSP1 was expressed and associated with Hsc70 in rat parotid acinar cells. Further, CSP1 associated with syntaxin 4, but not with syntaxin 3, on the apical plasma membrane. Introduction of anti-CSP1 antibody into SLO-permeabilized acinar cells enhanced isoproterenol (IPR)-induced amylase release. Introduction of GST-CSP11-112, containing both the J-domain and the adjacent linker region, enhanced IPR-induced amylase release, whereas neither GST-CSP11-82, containing the J-domain only, nor GST-CSP183-112, containing the linker region only, did produce detectable enhancement. These results indicated that both the J-domain and the linker domain of CSP1 are necessary to function an important role in acinar cell exocytosis.

  15. Salivary gland homeostasis is maintained through acinar cell self-duplication.

    PubMed

    Aure, Marit H; Konieczny, Stephen F; Ovitt, Catherine E

    2015-04-20

    Current dogma suggests that salivary gland homeostasis is stem cell dependent. However, the extent of stem cell contribution to salivary gland maintenance has not been determined. We investigated acinar cell replacement during homeostasis, growth, and regeneration, using an inducible CreER(T2) expressed under the control of the Mist1 gene locus. Genetic labeling, followed by a chase period, showed that acinar cell replacement is not driven by the differentiation of unlabeled stem cells. Analysis using R26(Brainbow2.1) reporter revealed continued proliferation and clonal expansion of terminally differentiated acinar cells in all major salivary glands. Induced injury also demonstrated the regenerative potential of pre-labeled acinar cells. Our results support a revised model for salivary gland homeostasis based predominantly on self-duplication of acinar cells, rather than on differentiation of stem cells. The proliferative capacity of differentiated acinar cells may prove critical in the implementation of cell-based strategies to restore the salivary glands.

  16. Integrin adhesion in regulation of lacrimal gland acinar cell secretion.

    PubMed

    Andersson, Sofia V; Hamm-Alvarez, Sarah F; Gierow, J Peter

    2006-09-01

    The extracellular microenvironment regulates lacrimal gland acinar cell secretion. Culturing isolated rabbit lacrimal gland acinar cells on different extracellular matrix proteins revealed that laminin enhances carbachol-stimulated secretion to a greater extent than other extracellular matrix proteins investigated. Furthermore, immunofluorescence indicated that integrin subunits, potentially functioning as laminin receptors are present in acinar cells. Among these, the integrin alpha6 and beta1 subunit mRNA expression was also confirmed by RT-PCR and sequence analysis. Secretion assays, which measured beta-hexosaminidase activity released in the culture media, demonstrated that function-blocking integrin alpha6 and beta1 monoclonal antibodies (mAbs) induce a rapid, transient and dose-dependent secretory response in cultured cells. To determine the intracellular pathways by which integrin alpha6 and beta1 mAbs could induce secretion, selected second messenger molecules were inhibited. Although inhibitors of protein kinase C and IP(3)-induced Ca(2+) mobilization attenuated carbachol-stimulated secretion, no effect on integrin mAb-induced release was observed. In addition, protein tyrosine kinases do not appear to have a role in transducing signals arising from mAb interactions. Our data clearly demonstrate, though, that cell adhesion through integrins regulates secretion from lacrimal gland acinar cells. The fact that the integrin mAbs affect the cholinergic response differently and that the integrin beta1 mAb secretion, but not the alpha6, was attenuated by the phosphatase inhibitor, sodium orthovanadate, suggests that each subunit utilizes separate intracellular signaling pathways to induce exocytosis. The results also indicate that the secretory response triggered by the beta1 integrin mAb is generated through dephosphorylation events.

  17. [Acinar cell carcinoma of submaxillary gland].

    PubMed

    Comeche, C; Calabuig, C; Barona, R

    1997-01-01

    Although acine cell neoplasms have for a long time been regarded as benign tumors, they are presently considered to represent the carcinomas. These rare tumors mainly affect the parotid glands, and only exceptionally involve other salivary glands. Clinically, acic cell carcinoma present as isolated tumors simulating a pleomorphic adenoma. The diagnosis is histopathological, and complete surgical removal of the tumor is the treatment of choice, with cervical lymphatic voiding and/or postoperative radiotherapy in selected cases. A prolonged patient follow-up is required, for the tumor may recur many years after surgery. We report a case of acinic cell carcinoma in submaxillary gland.

  18. Proteoglycans support proper granule formation in pancreatic acinar cells.

    PubMed

    Aroso, Miguel; Agricola, Brigitte; Hacker, Christian; Schrader, Michael

    2015-10-01

    Zymogen granules (ZG) are specialized organelles in the exocrine pancreas which allow digestive enzyme storage and regulated secretion. The molecular mechanisms of their biogenesis and the sorting of zymogens are still incompletely understood. Here, we investigated the role of proteoglycans in granule formation and secretion of zymogens in pancreatic AR42J cells, an acinar model system. Cupromeronic Blue cytochemistry and biochemical studies revealed an association of proteoglycans primarily with the granule membrane. Removal of proteoglycans by carbonate treatment led to a loss of membrane curvature indicating a supportive role in the maintenance of membrane shape and stability. Chemical inhibition of proteoglycan synthesis impaired the formation of normal electron-dense granules in AR42J cells and resulted in the formation of unusually small granule structures. These structures still contained the zymogen carboxypeptidase, a cargo molecule of secretory granules, but migrated to lighter fractions after density gradient centrifugation. Furthermore, the basal secretion of amylase was increased in AR42J cells after inhibitor treatment. In addition, irregular-shaped granules appeared in pancreatic lobules. We conclude that the assembly of a proteoglycan scaffold at the ZG membrane is supporting efficient packaging of zymogens and the proper formation of stimulus-competent storage granules in acinar cells of the pancreas.

  19. Pancreatic acinar cells: molecular insight from studies of signal-transduction using transgenic animals.

    PubMed

    Yule, David I

    2010-11-01

    Pancreatic acinar cells are classical exocrine gland cells. The apical regions of clusters of coupled acinar cells collectively form a lumen which constitutes the blind end of a tube created by ductal cells - a structure reminiscent of a "bunch of grapes". When activated by neural or hormonal secretagogues, pancreatic acinar cells are stimulated to secrete a variety of proteins. These proteins are predominately inactive digestive enzyme precursors called "zymogens". Acinar cell secretion is absolutely dependent on secretagogue-induced increases in intracellular free Ca(2+). The increase in [Ca(2+)](i) has precise temporal and spatial characteristics as a result of the exquisite regulation of the proteins responsible for Ca(2+) release, Ca(2+) influx and Ca(2+) clearance in the acinar cell. This brief review discusses recent studies in which transgenic animal models have been utilized to define in molecular detail the components of the Ca(2+) signaling machinery which contribute to these characteristics.

  20. PNA lectin for purifying mouse acinar cells from the inflamed pancreas

    PubMed Central

    Xiao, Xiangwei; Fischbach, Shane; Fusco, Joseph; Zimmerman, Ray; Song, Zewen; Nebres, Philip; Ricks, David Matthew; Prasadan, Krishna; Shiota, Chiyo; Husain, Sohail Z.; Gittes, George K.

    2016-01-01

    Better methods for purifying human or mouse acinar cells without the need for genetic modification are needed. Such techniques would be advantageous for the specific study of certain mechanisms, such as acinar-to-beta-cell reprogramming and pancreatitis. Ulex Europaeus Agglutinin I (UEA-I) lectin has been used to label and isolate acinar cells from the pancreas. However, the purity of the UEA-I-positive cell fraction has not been fully evaluated. Here, we screened 20 widely used lectins for their binding specificity for major pancreatic cell types, and found that UEA-I and Peanut agglutinin (PNA) have a specific affinity for acinar cells in the mouse pancreas, with minimal affinity for other major pancreatic cell types including endocrine cells, duct cells and endothelial cells. Moreover, PNA-purified acinar cells were less contaminated with mesenchymal and inflammatory cells, compared to UEA-I purified acinar cells. Thus, UEA-I and PNA appear to be excellent lectins for pancreatic acinar cell purification. PNA may be a better choice in situations where mesenchymal cells or inflammatory cells are significantly increased in the pancreas, such as type 1 diabetes, pancreatitis and pancreatic cancer. PMID:26884345

  1. The role of Ca2+ influx in endocytic vacuole formation in pancreatic acinar cells.

    PubMed

    Voronina, Svetlana; Collier, David; Chvanov, Michael; Middlehurst, Ben; Beckett, Alison J; Prior, Ian A; Criddle, David N; Begg, Malcolm; Mikoshiba, Katsuhiko; Sutton, Robert; Tepikin, Alexei V

    2015-02-01

    The inducers of acute pancreatitis trigger a prolonged increase in the cytosolic Ca(2+) concentration ([Ca(2+)]c), which is responsible for the damage to and eventual death of pancreatic acinar cells. Vacuolization is an important indicator of pancreatic acinar cell damage. Furthermore, activation of trypsinogen occurs in the endocytic vacuoles; therefore the vacuoles can be considered as 'initiating' organelles in the development of the cell injury. In the present study, we investigated the relationship between the formation of endocytic vacuoles and Ca(2+) influx developed in response to the inducers of acute pancreatitis [bile acid taurolithocholic acid 3-sulfate (TLC-S) and supramaximal concentration of cholecystokinin-8 (CCK)]. We found that the inhibitor of STIM (stromal interaction molecule)/Orai channels, GSK-7975A, effectively suppressed both the Ca(2+) influx (stimulated by inducers of pancreatitis) and the formation of endocytic vacuoles. Cell death induced by TLC-S or CCK was also inhibited by GSK-7975A. We documented the formation of endocytic vacuoles in response to store-operated Ca(2+) entry (SOCE) induced by thapsigargin [TG; inhibitor of sarcoplasmic/endoplasmic reticulum (ER) Ca(2+) pumps] and observed strong inhibition of TG-induced vacuole formation by GSK-7975A. Finally, we found that structurally-unrelated inhibitors of calpain suppress formation of endocytic vacuoles, suggesting that this Ca2+-dependent protease is a mediator between Ca(2+) elevation and endocytic vacuole formation.

  2. Acinar cell carcinoma of exocrine pancreas in two horses.

    PubMed

    de Brot, S; Junge, H; Hilbe, M

    2014-05-01

    Two horses were presented with non-specific clinical signs of several weeks' duration and were humanely destroyed due to a poor prognosis. At necropsy examination, both horses had multiple small, white nodules replacing pancreatic tissue and involving the serosal surface of the abdominal cavity, the liver and the lung. Microscopically, neoplastic cells were organized in acini and contained abundant (case 1) or sparse (horse 2) intracytoplasmic zymogen granules. Immunohistochemically, both tumours expressed amylase and pan-cytokeratin, but not insulin or neuron-specific enolase. In case 2, a low percentage of neoplastic cells expressed glucagon and synaptophysin. The presence of zymogen granules was confirmed in both cases by electron microscopy and occasional fibrillary or glucagon granules were observed in cases 1 and 2, respectively. A diagnosis of pancreatic acinar cell carcinoma was established in both horses.

  3. KRAS Mutations in Canine and Feline Pancreatic Acinar Cell Carcinoma.

    PubMed

    Crozier, C; Wood, G A; Foster, R A; Stasi, S; Liu, J H W; Bartlett, J M S; Coomber, B L; Sabine, V S

    2016-07-01

    Companion animals may serve as valuable models for studying human cancers. Although KRAS is the most commonly mutated gene in human ductal pancreatic cancers (57%), with mutations frequently occurring at codons 12, 13 and 61, human pancreatic acinar cell carcinomas (ACCs) lack activating KRAS mutations. In the present study, 32 pancreatic ACC samples obtained from 14 dogs and 18 cats, including seven metastases, were analyzed for six common activating KRAS mutations located in codons 12 (n = 5) and 13 (n = 1) using Sequenom MassARRAY. No KRAS mutations were found, suggesting that, similar to human pancreatic ACC, KRAS mutations do not play a critical role in feline or canine pancreatic ACC. Due to the similarity of the clinical disease in dogs and cats to that of man, this study confirms that companion animals offer potential as a suitable model for investigating this rare subtype of pancreatic carcinoma.

  4. Necro-inflammatory response of pancreatic acinar cells in the pathogenesis of acute alcoholic pancreatitis.

    PubMed

    Gu, H; Werner, J; Bergmann, F; Whitcomb, D C; Büchler, M W; Fortunato, F

    2013-01-01

    The role of pancreatic acinar cells in initiating necro-inflammatory responses during the early onset of alcoholic acute pancreatitis (AP) has not been fully evaluated. We investigated the ability of acinar cells to generate pro- and anti-inflammatory mediators, including inflammasome-associated IL-18/caspase-1, and evaluated acinar cell necrosis in an animal model of AP and human samples. Rats were fed either an ethanol-containing or control diet for 14 weeks and killed 3 or 24 h after a single lipopolysaccharide (LPS) injection. Inflammasome components and necro-inflammation were evaluated in acinar cells by immunofluorescence (IF), histology, and biochemical approaches. Alcohol exposure enhanced acinar cell-specific production of TNFα, IL-6, MCP-1 and IL-10, as early as 3 h after LPS, whereas IL-18 and caspase-1 were evident 24 h later. Alcohol enhanced LPS-induced TNFα expression, whereas blockade of LPS signaling diminished TNFα production in vitro, indicating that the response of pancreatic acinar cells to LPS is similar to that of immune cells. Similar results were observed from acinar cells in samples from patients with acute/recurrent pancreatitis. Although morphologic examination of sub-clinical AP showed no visible signs of necrosis, early loss of pancreatic HMGB1 and increased systemic levels of HMGB1 and LDH were observed, indicating that this strong systemic inflammatory response is associated with little pancreatic necrosis. These results suggest that TLR-4-positive acinar cells respond to LPS by activating the inflammasome and producing pro- and anti-inflammatory mediators during the development of mild, sub-clinical AP, and that these effects are exacerbated by alcohol injury.

  5. Necro-inflammatory response of pancreatic acinar cells in the pathogenesis of acute alcoholic pancreatitis

    PubMed Central

    Gu, H; Werner, J; Bergmann, F; Whitcomb, D C; Büchler, M W; Fortunato, F

    2013-01-01

    The role of pancreatic acinar cells in initiating necro-inflammatory responses during the early onset of alcoholic acute pancreatitis (AP) has not been fully evaluated. We investigated the ability of acinar cells to generate pro- and anti-inflammatory mediators, including inflammasome-associated IL-18/caspase-1, and evaluated acinar cell necrosis in an animal model of AP and human samples. Rats were fed either an ethanol-containing or control diet for 14 weeks and killed 3 or 24 h after a single lipopolysaccharide (LPS) injection. Inflammasome components and necro-inflammation were evaluated in acinar cells by immunofluorescence (IF), histology, and biochemical approaches. Alcohol exposure enhanced acinar cell-specific production of TNFα, IL-6, MCP-1 and IL-10, as early as 3 h after LPS, whereas IL-18 and caspase-1 were evident 24 h later. Alcohol enhanced LPS-induced TNFα expression, whereas blockade of LPS signaling diminished TNFα production in vitro, indicating that the response of pancreatic acinar cells to LPS is similar to that of immune cells. Similar results were observed from acinar cells in samples from patients with acute/recurrent pancreatitis. Although morphologic examination of sub-clinical AP showed no visible signs of necrosis, early loss of pancreatic HMGB1 and increased systemic levels of HMGB1 and LDH were observed, indicating that this strong systemic inflammatory response is associated with little pancreatic necrosis. These results suggest that TLR-4-positive acinar cells respond to LPS by activating the inflammasome and producing pro- and anti-inflammatory mediators during the development of mild, sub-clinical AP, and that these effects are exacerbated by alcohol injury. PMID:24091659

  6. Basal autophagy maintains pancreatic acinar cell homeostasis and protein synthesis and prevents ER stress

    PubMed Central

    Antonucci, Laura; Fagman, Johan B.; Kim, Ju Youn; Todoric, Jelena; Gukovsky, Ilya; Mackey, Mason; Ellisman, Mark H.; Karin, Michael

    2015-01-01

    Pancreatic acinar cells possess very high protein synthetic rates as they need to produce and secrete large amounts of digestive enzymes. Acinar cell damage and dysfunction cause malnutrition and pancreatitis, and inflammation of the exocrine pancreas that promotes development of pancreatic ductal adenocarcinoma (PDAC), a deadly pancreatic neoplasm. The cellular and molecular mechanisms that maintain acinar cell function and whose dysregulation can lead to tissue damage and chronic pancreatitis are poorly understood. It was suggested that autophagy, the principal cellular degradative pathway, is impaired in pancreatitis, but it is unknown whether impaired autophagy is a cause or a consequence of pancreatitis. To address this question, we generated Atg7Δpan mice that lack the essential autophagy-related protein 7 (ATG7) in pancreatic epithelial cells. Atg7Δpan mice exhibit severe acinar cell degeneration, leading to pancreatic inflammation and extensive fibrosis. Whereas ATG7 loss leads to the expected decrease in autophagic flux, it also results in endoplasmic reticulum (ER) stress, accumulation of dysfunctional mitochondria, oxidative stress, activation of AMPK, and a marked decrease in protein synthetic capacity that is accompanied by loss of rough ER. Atg7Δpan mice also exhibit spontaneous activation of regenerative mechanisms that initiate acinar-to-ductal metaplasia (ADM), a process that replaces damaged acinar cells with duct-like structures. PMID:26512112

  7. Effect of sialodacryoadenitis virus exposure on acinar epithelial cells from the rat lacrimal gland.

    PubMed

    Wickham, L A; Huang, Z; Lambert, R W; Sullivan, D A

    1997-09-01

    Sialodacryoadenitis virus (SDAV), a RNA coronavirus, induces degenerative, necrotic and atrophic alterations in acinar epithelial cells of the rat lacrimal gland. To begin to explore the underlying mechanism(s) of this viral effect, we sought in the present study to: (1) determine whether SDAV invades and replicates in lacrimal gland acinar cells in vitro and (2) assess whether short-term SDAV challenge interferes with the viability or function of acinar cells in vitro. For comparison we also evaluated the relative infectivity of SDAV in acinar epithelial cells from lacrimal, submandibular and parotid glands, given that salivary tissues are known to be highly susceptible to SDAV infection in vivo. Acinar epithelial cells from lacrimal, submandibular or parotid glands were isolated from male rats, exposed briefly to SDAV or control cell antigen and then cultured for four, eight or twelve days. At experimental termination, SDAV titers in both media and sonicated cell extracts were evaluated by plaque assay titration on mouse L2 cell monolayers. To evaluate functional aspects of lacrimal gland acinar cells, SDAV-infected cells were incubated in the presence or absence of dihydrotestosterone and culture media were analyzed by RIA to measure the extent of the androgen-induced increase in secretory component (SC) production. Our results showed that: (1) SDAV invades and replicates in lacrimal gland acinar cells, Viral challenge resulted in a significant, time-dependent increase in SDAV titers, that were primarily cell-associated and greatly exceeded amounts contained in the original inoculum; (2) SDAV infection did not compromise lacrimal acinar cell viability or prevent the cellular SC response to androgens. Viral presence, though, did often attenuate the magnitude of this hormone action; and (3) SDAV infects salivary acinar cells, but the kinetics and magnitude or viral replication in lacrimal, submandibular and parotid cells showed considerable variations. These

  8. Marked differences in immunocytological localization of ( sup 3 H)estradiol-binding protein in rat pancreatic acinar tumor cells compared to normal acinar cells

    SciTech Connect

    Beaudoin, A.R.; Grondin, G.; St Jean, P.; Pettengill, O.; Longnecker, D.S.; Grossman, A. )

    1991-03-01

    ({sup 3}H)Estradiol can bind to a specific protein in normal rat pancreatic acinar cells. Electron microscopic immunocytochemical analysis has shown this protein to be localized primarily in the rough endoplasmic reticulum and mitochondria. Rat exocrine pancreatic tumor cell lines, whether grown in tissue culture (AR42J) or as a tumor mass after sc injection into rats (DSL-2), lacked detectable amounts of this ({sup 3}H)estradiol-binding protein (EBP), as determined by the dextran-coated charcoal assay. Furthermore, primary exocrine pancreatic neoplasms induced with the carcinogen azaserine contained little or no detectable ({sup 3}H)estradiol-binding activity. However, electron immunocytochemical studies of transformed cells indicated the presence of material that cross-reacted with antibodies prepared against the ({sup 3}H)EBP. The immunopositive reaction in transformed cells was localized almost exclusively in lipid granules. Such lipid organelles in normal acinar cells, although present less frequently than in transformed cells, have never been observed to contain EBP-like immunopositive material. Presumably, the aberrant localization of EBP in these acinar tumor cells results in loss of function of this protein, which in normal pancreatic acinar cells appears to exert a modulating influence on zymogen granule formation and the process of secretion.

  9. Formation of salivary acinar cell spheroids in vitro above a polyvinyl alcohol-coated surface.

    PubMed

    Chen, Min-Huey; Chen, Yi-Jane; Liao, Chih-Chen; Chan, Yen-Hui; Lin, Chia-Yung; Chen, Rung-Shu; Young, Tai-Hong

    2009-09-15

    Tissue engineering of salivary glands offers the potential for future use in the treatment of patients with salivary hypofunction. Biocompatible materials that promote acinar cell aggregation and function in vitro are an essential part of salivary gland tissue engineering. In this study, rat parotid acinar cells assembled into three-dimensional aggregates above the polyvinyl alcohol (PVA)-coated surface. These aggregates developed compact acinar cell spheroids resembling in vivo physiological condition, which were different from the traditional monolayered morphology in vitro. Cells remained viable and with better functional activity in response to acetylcholine in the spheroids and could form monolayered acinar cells when they were reinoculated on tissue culture polystyrene wells. To interpret the phenomenon further, we proposed that the formation of acinar cell spheroids on the PVA is mediated by a balance between two competing forces: the interactions of cell-PVA and cell-cell. This study demonstrated the formation of functional cell spheroids above a PVA-coated surface may provide an in vitro system for investigating cell behaviors for tissue engineering of artificial salivary gland.

  10. Characterization of single potassium channels in mouse pancreatic acinar cells.

    PubMed Central

    Schmid, A; Schulz, I

    1995-01-01

    1. Single K(+)-selective channels with a conductance of about 48 pS (pipette, 145 mM KCl; bath, 140 mM NaCl + 4.7 mM KCl) were recorded in the patch-clamp whole-cell configuration in isolated mouse pancreatic acinar cells. 2. Neither application of the secretagogues acetylcholine (second messenger, inositol 1,4,5-trisphosphate) or secretin (second messenger, cAMP), nor addition of the catalytic subunit of protein kinase A to the pipette solution changed the activity of the 48 pS K+ channel. 3. Intracellular acidification with sodium propionate (20 mM) diminished activity of the 48 pS channel, whereas channel open probability was increased by cytosolic alkalization with 20 mM NH4Cl. 4. BaCl2 (5 mM), TEA (10 mM) or apamin (1 microM) added to the bath solution had no obvious effect on the kinetics of the 48 pS channel. Similarly, glibenclamide and diazoxide failed to influence the channel activity. 5. When extracellular NaCl was replaced by KCl, whole-cell recordings revealed an inwardly rectifying K+ current carried by a 17 pS K+ channel. 6. The inwardly rectifying K+ current was not pH dependent and could largely be blocked by Ba2+ but not by TEA. 7. Since the 48 pS K+ channel is neither Ca2+ nor cAMP regulated, we suggest that this channel could play a role in the maintenance of the negative cell resting potential. PMID:7623283

  11. Low-level (gallium-aluminum-arsenide) laser irradiation of Par-C10 cells and acinar cells of rat parotid gland.

    PubMed

    Onizawa, Katsuhiro; Muramatsu, Takashi; Matsuki, Miwako; Ohta, Kazumasa; Matsuzaka, Kenichi; Oda, Yutaka; Shimono, Masaki

    2009-03-01

    We investigated cell response, including cell proliferation and expression of heat stress protein and bcl-2, to clarify the influence of low-level [gallium-aluminum-arsenide (Ga-Al-As) diode] laser irradiation on Par-C10 cells derived from the acinar cells of rat parotid glands. Furthermore, we also investigated amylase release and cell death from irradiation in acinar cells from rat parotid glands. The number of Par-C10 cells in the laser-irradiated groups was higher than that in the non-irradiated group at days 5 and 7, and the difference was statistically significant (P < 0.01). Greater expression of heat shock protein (HSP)25 and bcl-2 was seen on days 1 and 3 in the irradiated group. Assay of the released amylase showed no significant difference statistically between the irradiated group and the non-irradiated group. Trypan blue exclusion assay revealed that there was no difference in the ratio of dead to live cells between the irradiated and the non-irradiated groups. These results suggest that low-level laser irradiation promotes cell proliferation and expression of anti-apoptosis proteins in Par-C10 cells, but it does not significantly affect amylase secretion and does not induce rapid cell death in isolated acinar cells from rat parotid glands.

  12. Acinar cell-specific knockout of the PTHrP gene decreases the proinflammatory and profibrotic responses in pancreatitis

    PubMed Central

    Bhatia, Vandanajay; Rastellini, Cristiana; Han, Song; Aronson, Judith F.; Greeley, George H.

    2014-01-01

    Pancreatitis is a necroinflammatory disease with acute and chronic manifestations. Accumulated damage incurred during repeated bouts of acute pancreatitis (AP) can lead to chronic pancreatitis (CP). Pancreatic parathyroid hormone-related protein (PTHrP) levels are elevated in a mouse model of cerulein-induced AP. Here, we show elevated PTHrP levels in mouse models of pancreatitis induced by chronic cerulein administration and pancreatic duct ligation. Because acinar cells play a major role in the pathophysiology of pancreatitis, mice with acinar cell-specific targeted disruption of the Pthrp gene (PTHrPΔacinar) were generated to assess the role of acinar cell-secreted PTHrP in pancreatitis. These mice were generated using Cre-LoxP technology and the acinar cell-specific elastase promoter. PTHrPΔacinar exerted protective effects in cerulein and pancreatic duct ligation models, evident as decreased edema, histological damage, amylase secretion, pancreatic stellate cell (PSC) activation, and extracellular matrix deposition. Treating acinar cells in vitro with cerulein increased IL-6 expression and NF-κB activity; these effects were attenuated in PTHrPΔacinar cells, as were the cerulein- and carbachol-induced elevations in amylase secretion. The cerulein-induced upregulation of procollagen I expression was lost in PSCs from PTHrPΔacinar mice. PTHrP immunostaining was elevated in human CP sections. The cerulein-induced upregulation of IL-6 and ICAM-1 (human acinar cells) and procollagen I (human PSCs) was suppressed by pretreatment with the PTH1R antagonist, PTHrP (7–34). These findings establish PTHrP as a novel mediator of inflammation and fibrosis associated with CP. Acinar cell-secreted PTHrP modulates acinar cell function via its effects on proinflammatory cytokine release and functions via a paracrine pathway to activate PSCs. PMID:25035110

  13. A Computer-Based Automated Algorithm for Assessing Acinar Cell Loss after Experimental Pancreatitis

    PubMed Central

    Eisses, John F.; Davis, Amy W.; Tosun, Akif Burak; Dionise, Zachary R.; Chen, Cheng; Ozolek, John A.; Rohde, Gustavo K.; Husain, Sohail Z.

    2014-01-01

    The change in exocrine mass is an important parameter to follow in experimental models of pancreatic injury and regeneration. However, at present, the quantitative assessment of exocrine content by histology is tedious and operator-dependent, requiring manual assessment of acinar area on serial pancreatic sections. In this study, we utilized a novel computer-generated learning algorithm to construct an accurate and rapid method of quantifying acinar content. The algorithm works by learning differences in pixel characteristics from input examples provided by human experts. HE-stained pancreatic sections were obtained in mice recovering from a 2-day, hourly caerulein hyperstimulation model of experimental pancreatitis. For training data, a pathologist carefully outlined discrete regions of acinar and non-acinar tissue in 21 sections at various stages of pancreatic injury and recovery (termed the “ground truth”). After the expert defined the ground truth, the computer was able to develop a prediction rule that was then applied to a unique set of high-resolution images in order to validate the process. For baseline, non-injured pancreatic sections, the software demonstrated close agreement with the ground truth in identifying baseline acinar tissue area with only a difference of 1%±0.05% (p = 0.21). Within regions of injured tissue, the software reported a difference of 2.5%±0.04% in acinar area compared with the pathologist (p = 0.47). Surprisingly, on detailed morphological examination, the discrepancy was primarily because the software outlined acini and excluded inter-acinar and luminal white space with greater precision. The findings suggest that the software will be of great potential benefit to both clinicians and researchers in quantifying pancreatic acinar cell flux in the injured and recovering pancreas. PMID:25343460

  14. The small GTPase Rab33A participates in regulation of amylase release from parotid acinar cells.

    PubMed

    Imai, Akane; Tsujimura, Maiko; Yoshie, Sumio; Fukuda, Mitsunori

    2015-06-01

    Amylase is released from exocrine parotid acinar cells via typical exocytosis. Exocytosis of amylase-containing granules occurs through several steps, including formation, maturation, and transport of granules. These steps are thought to be regulated by members of the small GTPase Rab family. We previously demonstrated that Rab27 and its effectors mediate amylase release from parotid acinar cells, but the functional involvement of other Rab proteins in exocrine granule exocytosis remains largely unknown. Here, we studied isoproterenol (IPR)-induced amylase release from parotid acinar cells to investigate the possible involvement of Rab33A, which was recently suggested to regulate exocytosis in hippocampal neurons and PC12 cells. Rab33A was endogenously expressed in parotid acinar cells and present in secretory granules and the Golgi body. Functional ablation of Rab33A with anti-Rab33A antibody or a dominant-negative Rab33A-T50N mutant significantly reduced IPR-induced amylase release. Our results indicated that Rab33A is a novel component of IPR-stimulated amylase secretion from parotid acinar cells.

  15. Activation of Soluble Adenylyl Cyclase Protects against Secretagogue Stimulated Zymogen Activation in Rat Pancreaic Acinar Cells

    PubMed Central

    Kolodecik, Thomas R.; Shugrue, Christine A.; Thrower, Edwin C.; Levin, Lonny R.; Buck, Jochen; Gorelick, Fred S.

    2012-01-01

    An early feature of acute pancreatitis is activation of zymogens, such as trypsinogen, within the pancreatic acinar cell. Supraphysiologic concentrations of the hormone cholecystokinin (CCK; 100 nM), or its orthologue cerulein (CER), induce zymogen activation and elevate levels of cAMP in pancreatic acinar cells. The two classes of adenylyl cyclase, trans-membrane (tmAC) and soluble (sAC), are activated by distinct mechanisms, localize to specific subcellular domains, and can produce locally high concentrations of cAMP. We hypothesized that sAC activity might selectively modulate acinar cell zymogen activation. sAC was identified in acinar cells by PCR and immunoblot. It localized to the apical region of the cell under resting conditions and redistributed intracellularly after treatment with supraphysiologic concentrations of cerulein. In cerulein-treated cells, pre-incubation with a trans-membrane adenylyl cyclase inhibitor did not affect zymogen activation or amylase secretion. However, treatment with a sAC inhibitor (KH7), or inhibition of a downstream target of cAMP, protein kinase A (PKA), significantly enhanced secretagogue-stimulated zymogen activation and amylase secretion. Activation of sAC with bicarbonate significantly inhibited secretagogue-stimulated zymogen activation; this response was decreased by inhibition of sAC or PKA. Bicarbonate also enhanced secretagogue-stimulated cAMP accumulation; this effect was inhibited by KH7. Bicarbonate treatment reduced secretagogue-stimulated acinar cell vacuolization, an early marker of pancreatitis. These data suggest that activation of sAC in the pancreatic acinar cell has a protective effect and reduces the pathologic activation of proteases during pancreatitis. PMID:22844459

  16. Protein kinase D1 drives pancreatic acinar cell reprogramming and progression to intraepithelial neoplasia

    NASA Astrophysics Data System (ADS)

    Liou, Geou-Yarh; Döppler, Heike; Braun, Ursula B.; Panayiotou, Richard; Scotti Buzhardt, Michele; Radisky, Derek C.; Crawford, Howard C.; Fields, Alan P.; Murray, Nicole R.; Wang, Q. Jane; Leitges, Michael; Storz, Peter

    2015-02-01

    The transdifferentiation of pancreatic acinar cells to a ductal phenotype (acinar-to-ductal metaplasia, ADM) occurs after injury or inflammation of the pancreas and is a reversible process. However, in the presence of activating Kras mutations or persistent epidermal growth factor receptor (EGF-R) signalling, cells that underwent ADM can progress to pancreatic intraepithelial neoplasia (PanIN) and eventually pancreatic cancer. In transgenic animal models, ADM and PanINs are initiated by high-affinity ligands for EGF-R or activating Kras mutations, but the underlying signalling mechanisms are not well understood. Here, using a conditional knockout approach, we show that protein kinase D1 (PKD1) is sufficient to drive the reprogramming process to a ductal phenotype and progression to PanINs. Moreover, using 3D explant culture of primary pancreatic acinar cells, we show that PKD1 acts downstream of TGFα and Kras, to mediate formation of ductal structures through activation of the Notch pathway.

  17. Transgenic Expression of a Single Transcription Factor Pdx1 Induces Transdifferentiation of Pancreatic Acinar Cells to Endocrine Cells in Adult Mice.

    PubMed

    Miyazaki, Satsuki; Tashiro, Fumi; Miyazaki, Jun-Ichi

    2016-01-01

    A promising approach to new diabetes therapies is to generate β cells from other differentiated pancreatic cells in vivo. Because the acinar cells represent the most abundant cell type in the pancreas, an attractive possibility is to reprogram acinar cells into β cells. The transcription factor Pdx1 (Pancreas/duodenum homeobox protein 1) is essential for pancreatic development and cell lineage determination. Our objective is to examine whether exogenous expression of Pdx1 in acinar cells of adult mice might induce reprogramming of acinar cells into β cells. We established a transgenic mouse line in which Pdx1 and EGFP (enhanced green fluorescent protein) could be inducibly expressed in the acinar cells. After induction of Pdx1, we followed the acinar cells for their expression of exocrine and endocrine markers using cell-lineage tracing with EGFP. The acinar cell-specific expression of Pdx1 in adult mice reprogrammed the acinar cells as endocrine precursor cells, which migrated into the pancreatic islets and differentiated into insulin-, somatostatin-, or PP (pancreatic polypeptide)-producing endocrine cells, but not into glucagon-producing cells. When the mice undergoing such pancreatic reprogramming were treated with streptozotocin (STZ), the newly generated insulin-producing cells were able to ameliorate STZ-induced diabetes. This paradigm of in vivo reprogramming indicates that acinar cells hold promise as a source for new islet cells in regenerative therapies for diabetes. PMID:27526291

  18. Transgenic Expression of a Single Transcription Factor Pdx1 Induces Transdifferentiation of Pancreatic Acinar Cells to Endocrine Cells in Adult Mice

    PubMed Central

    Miyazaki, Satsuki; Tashiro, Fumi; Miyazaki, Jun-ichi

    2016-01-01

    A promising approach to new diabetes therapies is to generate β cells from other differentiated pancreatic cells in vivo. Because the acinar cells represent the most abundant cell type in the pancreas, an attractive possibility is to reprogram acinar cells into β cells. The transcription factor Pdx1 (Pancreas/duodenum homeobox protein 1) is essential for pancreatic development and cell lineage determination. Our objective is to examine whether exogenous expression of Pdx1 in acinar cells of adult mice might induce reprogramming of acinar cells into β cells. We established a transgenic mouse line in which Pdx1 and EGFP (enhanced green fluorescent protein) could be inducibly expressed in the acinar cells. After induction of Pdx1, we followed the acinar cells for their expression of exocrine and endocrine markers using cell-lineage tracing with EGFP. The acinar cell-specific expression of Pdx1 in adult mice reprogrammed the acinar cells as endocrine precursor cells, which migrated into the pancreatic islets and differentiated into insulin-, somatostatin-, or PP (pancreatic polypeptide)-producing endocrine cells, but not into glucagon-producing cells. When the mice undergoing such pancreatic reprogramming were treated with streptozotocin (STZ), the newly generated insulin-producing cells were able to ameliorate STZ-induced diabetes. This paradigm of in vivo reprogramming indicates that acinar cells hold promise as a source for new islet cells in regenerative therapies for diabetes. PMID:27526291

  19. Alcohol oxidizing enzymes and ethanol-induced cytotoxicity in rat pancreatic acinar AR42J cells

    PubMed Central

    Bhopale, Kamlesh K.; Falzon, Miriam; Ansari, G. A. S.

    2016-01-01

    Alcoholic chronic pancreatitis (ACP) is a serious inflammatory disease causing significant morbidity and mortality. Due to lack of a suitable animal model, the underlying mechanism of ACP is poorly understood. Chronic alcohol abuse inhibits alcohol dehydrogenase (ADH) and facilitates nonoxidative metabolism of ethanol to fatty acid ethyl esters (FAEEs) in the pancreas frequently damaged during chronic ethanol abuse. Earlier, we reported a concentration-dependent formation of FAEEs and cytotoxicity in ethanol-treated rat pancreatic tumor (AR42J) cells, which express high FAEE synthase activity as compared to ADH and cytochrome P450 2E1. Therefore, the present study was undertaken to investigate the role of various ethanol oxidizing enzymes in ethanol-induced pancreatic acinar cell injury. Confluent AR42J cells were pre-treated with inhibitors of ADH class I and II [4-methylpyrazole (MP)] or class I, II, and III [1,10-phenanthroline (PT)], cytochrome P450 2E1 (trans-1,2-dichloroethylene) or catalase (sodium azide) followed by incubation with 800 mg% ethanol at 37°C for 6 h. Ethanol metabolism, cell viability, cytotoxicity (apoptosis and necrosis), cell proliferation status, and formation of FAEEs in AR42J cells were measured. The cell viability and cell proliferation rate were significantly reduced in cells pretreated with 1,10-PT + ethanol followed by those with 4-MP + ethanol. In situ formation of FAEEs was twofold greater in cells incubated with l,10-PT + ethanol and ~1.5-fold in those treated with 4-MP + ethanol vs. respective controls. However, cells treated with inhibitors of cytochrome P450 2E1 or catalase in combination of ethanol showed no significant changes either for FAEE formation, cell death or proliferation rate. Therefore, an impaired ADH class I—III catalyzed oxidation of ethanol appears to be a key contributing factor in ethanol-induced pancreatic injury via formation of nonoxidative metabolites of ethanol. PMID:24281792

  20. Alcohol oxidizing enzymes and ethanol-induced cytotoxicity in rat pancreatic acinar AR42J cells.

    PubMed

    Bhopale, Kamlesh K; Falzon, Miriam; Ansari, G A S; Kaphalia, Bhupendra S

    2014-04-01

    Alcoholic chronic pancreatitis (ACP) is a serious inflammatory disease causing significant morbidity and mortality. Due to lack of a suitable animal model, the underlying mechanism of ACP is poorly understood. Chronic alcohol abuse inhibits alcohol dehydrogenase (ADH) and facilitates nonoxidative metabolism of ethanol to fatty acid ethyl esters (FAEEs) in the pancreas frequently damaged during chronic ethanol abuse. Earlier, we reported a concentration-dependent formation of FAEEs and cytotoxicity in ethanol-treated rat pancreatic tumor (AR42J) cells, which express high FAEE synthase activity as compared to ADH and cytochrome P450 2E1. Therefore, the present study was undertaken to investigate the role of various ethanol oxidizing enzymes in ethanol-induced pancreatic acinar cell injury. Confluent AR42J cells were pre-treated with inhibitors of ADH class I and II [4-methylpyrazole (MP)] or class I, II, and III [1,10-phenanthroline (PT)], cytochrome P450 2E1 (trans-1,2-dichloroethylene) or catalase (sodium azide) followed by incubation with 800 mg% ethanol at 37°C for 6 h. Ethanol metabolism, cell viability, cytotoxicity (apoptosis and necrosis), cell proliferation status, and formation of FAEEs in AR42J cells were measured. The cell viability and cell proliferation rate were significantly reduced in cells pretreated with 1,10-PT + ethanol followed by those with 4-MP + ethanol. In situ formation of FAEEs was twofold greater in cells incubated with 1,10-PT + ethanol and ∼1.5-fold in those treated with 4-MP + ethanol vs. respective controls. However, cells treated with inhibitors of cytochrome P450 2E1 or catalase in combination of ethanol showed no significant changes either for FAEE formation, cell death or proliferation rate. Therefore, an impaired ADH class I-III catalyzed oxidation of ethanol appears to be a key contributing factor in ethanol-induced pancreatic injury via formation of nonoxidative metabolites of ethanol.

  1. Metabotropic glutamate receptor 1 disrupts mammary acinar architecture and initiates malignant transformation of mammary epithelial cells.

    PubMed

    Teh, Jessica L F; Shah, Raj; La Cava, Stephanie; Dolfi, Sonia C; Mehta, Madhura S; Kongara, Sameera; Price, Sandy; Ganesan, Shridar; Reuhl, Kenneth R; Hirshfield, Kim M; Karantza, Vassiliki; Chen, Suzie

    2015-05-01

    Metabotropic glutamate receptor 1 (mGluR1/Grm1) is a member of the G-protein-coupled receptor superfamily, which was once thought to only participate in synaptic transmission and neuronal excitability, but has more recently been implicated in non-neuronal tissue functions. We previously described the oncogenic properties of Grm1 in cultured melanocytes in vitro and in spontaneous melanoma development with 100 % penetrance in vivo. Aberrant mGluR1 expression was detected in 60-80 % of human melanoma cell lines and biopsy samples. As most human cancers are of epithelial origin, we utilized immortalized mouse mammary epithelial cells (iMMECs) as a model system to study the transformative properties of Grm1. We introduced Grm1 into iMMECs and isolated several stable mGluR1-expressing clones. Phenotypic alterations in mammary acinar architecture were assessed using three-dimensional morphogenesis assays. We found that mGluR1-expressing iMMECs exhibited delayed lumen formation in association with decreased central acinar cell death, disrupted cell polarity, and a dramatic increase in the activation of the mitogen-activated protein kinase pathway. Orthotopic implantation of mGluR1-expressing iMMEC clones into mammary fat pads of immunodeficient nude mice resulted in mammary tumor formation in vivo. Persistent mGluR1 expression was required for the maintenance of the tumorigenic phenotypes in vitro and in vivo, as demonstrated by an inducible Grm1-silencing RNA system. Furthermore, mGluR1 was found be expressed in human breast cancer cell lines and breast tumor biopsies. Elevated levels of extracellular glutamate were observed in mGluR1-expressing breast cancer cell lines and concurrent treatment of MCF7 xenografts with glutamate release inhibitor, riluzole, and an AKT inhibitor led to suppression of tumor progression. Our results are likely relevant to human breast cancer, highlighting a putative role of mGluR1 in the pathophysiology of breast cancer and the potential

  2. Intracellular calcium signalling in rat parotid acinar cells that lack secretory vesicles.

    PubMed Central

    Liu, P; Scott, J; Smith, P M

    1998-01-01

    Secretory vesicles from pancreatic acinar cells have recently been shown to release Ca2+ after stimulation with Ins(1,4,5)P3 [Gerasimenko, Gerasimenko, Belan and Petersen, (1996) Cell 84, 473-480]. These observations have been used in support of the hypothesis that Ca2+ release from secretory vesicles could be an important component of stimulus secretion coupling in exocrine acinar cells. In the rat, ligation of the parotid duct causes a reversible atrophy of the parotid gland. Most notably, after atrophy the acinar cells are reduced in size and no longer contain secretory vesicles [Liu, Smith, and Scott (1996) J. Dent. Res. 74, 900]. We have measured cytosolic free-Ca2+ concentration ([Ca2+]i) in single, acutely isolated, rat parotid acinar cells, and compared Ca2+ mobilization in response to acetylcholine (ACh) stimulation in cells obtained from control animals to that in cells lacking secretory vesicles obtained after atrophy of the parotid gland. Application of 50-5000 nM ACh to control cells gave rise to a typical, dose-dependent, biphasic increase in [Ca2+]i, of which the later, plateau, phase was acutely dependent on the extracellular Ca2+ concentration. An identical pattern of response was observed with cells obtained from atrophic glands. Low concentrations of ACh (10-100 nM) occasionally produced [Ca2+]i oscillations of a similar pattern in cells from both control and atrophic glands. We were able to show that Ca2+ rises first in the apical pole of the cell and the increase then spreads to the rest of the cell in cells from control glands but not in cells from atrophic glands. However, at present we are unable to determine whether this is due to the lack of secretory vesicles or whether the separation is too small to measure in the smaller acinar cells obtained from atrophic glands. We conclude therefore, that secretory vesicles make no significant contribution to overall Ca2+ mobilization in rat parotid acinar cells, nor are they required for oscillatory

  3. [Vital fluorochrome staining of isolated pancreatic acinar cells for the characterization of cell-structural changes].

    PubMed

    Dietzmann, K; Letko, G; Spormann, H

    1986-01-01

    Rhodamine 6 G as a cationic fluorophore is demonstrated to be selectively accumulated by mitochondria of living pancreatic acinar cells (cell isolation see Spormann et al. [1986]. The accumulation of rhodamine was studied under using of electron transport inhibitors, ionophores and some hydrogen donors. The application of DNP as wellknown protonophore resulted in a rapid dissipation of any fluorescent signals, whereas application of sodium succinate, hyperosmolaric exhibited a remarkable increase of fluorescence intensity. Using this technique it is possible to estimate the energy state of living cells under various conditions of energy supply and demand. PMID:2426729

  4. Salivary gland acinar cells regenerate functional glandular structures in modified hydrogels

    NASA Astrophysics Data System (ADS)

    Pradhan, Swati

    Xerostomia, a condition resulting from irradiation of the head and neck, affects over 40,000 cancer patients each year in the United States. Direct radiation damage of the acinar cells that secrete fluid and protein results in salivary gland hypofunction. Present medical management for xerostomia for patients treated for upper respiratory cancer is largely ineffective. Patients who have survived their terminal diagnosis are often left with a diminished quality of life and are unable to enjoy the simple pleasures of eating and drinking. This project aims to ultimately reduce human suffering by developing a functional implantable artificial salivary gland. The goal was to create an extracellular matrix (ECM) modified hyaluronic acid (HA) based hydrogel culture system that allows for the growth and differentiation of salivary acinar cells into functional acini-like structures capable of secreting large amounts of protein and fluid unidirectionally and to ultimately engineer a functional artificial salivary gland that can be implanted into an animal model. A tissue collection protocol was established and salivary gland tissue was obtained from patients undergoing head and neck surgery. The tissue specimen was assessed by histology and immunohistochemistry to establish the phenotype of normal salivary gland cells including the native basement membranes. Hematoxylin and eosin staining confirmed normal glandular tissue structures including intercalated ducts, striated ducts and acini. alpha-Amylase and periodic acid schiff stain, used for structures with a high proportion of carbohydrate macromolecules, preferentially stained acinar cells in the tissue. Intercalated and striated duct structures were identified using cytokeratins 19 and 7 staining. Myoepithelial cells positive for cytokeratin 14 were found wrapped around the serous and mucous acini. Tight junction components including ZO-1 and E-cadherin were present between both ductal and acinar cells. Ductal and acinar

  5. Epiregulin is critical for the acinar cell regeneration of the submandibular gland in a mouse duct ligation model.

    PubMed

    Nagai, Koichi; Arai, Hideo; Okudera, Michisato; Yamamura, Takashi; Oki, Hidero; Komiyama, Kazuo

    2014-05-01

    Acinar cell regeneration from tubular structures has been reported to occur in duct-deligated salivary glands. However, the detailed process of acinar cell regeneration has not been clarified. We have developed a mouse duct ligation model to clarify the mechanisms underlying acinar cell regeneration, and we analyzed the epidermal growth factor receptor (EGFR) and epidermal growth factor (EGF) ligands using the model. We studied these ligands expressions in the course of acinar cell regeneration using immunohistochemistry and RT-PCR methods. In the duct-ligated portion of the submandibular gland (SMG) that underwent atrophy, newly formed acinar cells were observed arising from the tubular structures after the release of the duct obstruction. The constitutive expression of EGFR was observed by immunohistochemistry in both the duct-ligated and duct-deligated animals as well as in normal controls. The EGFR phosphorylation detected on the tubular structures after duct ligation paralleled the acinar cell regeneration. RT-PCR showed an increase in the epiregulin and heparin-binding EGF levels from day 0 to day 3 after the release of the duct obstruction. The EGF level was increased only after day 7. In vitro, cultured cells isolated from ligated SMGs proliferated and produced EGF ligands following the addition of epiregulin to the culture medium. These findings suggest that the tubular structures localized in an atrophic gland are the source of acinar cell regeneration of the salivary gland. The induction of EGF ligands, in particular epiregulin, may play an important role in acinar cell regeneration in this model.

  6. Analysis of changes in the expression pattern of claudins using salivary acinar cells in primary culture.

    PubMed

    Fujita-Yoshigaki, Junko

    2011-01-01

    Primary saliva is produced from blood plasma in the acini of salivary glands and is modified by ion adsorption and secretion as the saliva passes through the ducts. In rodents, acinar cells of salivary glands express claudin-3 but not claudin-4, whereas duct cells express both claudins-3 and -4. The distinct claudin expression patterns may reflect differences in the permeability of tight junctions between acinar and duct cells. To analyze the role of claudins in salivary glands, we established a system for the primary culture of parotid acinar cells, where the expression patterns of claudins are remarkably changed. Real-time RT-PCR and immunoblot analyses reveal that the expression levels of claudins-4 and -6 increased, whereas claudins-3 and -10 decreased. We found that the signal to induce those changes is triggered during cell isolation and is mediated by Src and p38 MAP kinase. Here, we introduce the methods used to determine the signal pathway that induces the change in claudin expression.

  7. Inhibitors of ORAI1 Prevent Cytosolic Calcium-Associated Injury of Human Pancreatic Acinar Cells and Acute Pancreatitis in 3 Mouse Models

    PubMed Central

    Wen, Li; Voronina, Svetlana; Javed, Muhammad A.; Awais, Muhammad; Szatmary, Peter; Latawiec, Diane; Chvanov, Michael; Collier, David; Huang, Wei; Barrett, John; Begg, Malcolm; Stauderman, Ken; Roos, Jack; Grigoryev, Sergey; Ramos, Stephanie; Rogers, Evan; Whitten, Jeff; Velicelebi, Gonul; Dunn, Michael; Tepikin, Alexei V.; Criddle, David N.; Sutton, Robert

    2015-01-01

    Background & Aims Sustained activation of the cytosolic calcium concentration induces injury to pancreatic acinar cells and necrosis. The calcium release–activated calcium modulator ORAI1 is the most abundant Ca2+ entry channel in pancreatic acinar cells; it sustains calcium overload in mice exposed to toxins that induce pancreatitis. We investigated the roles of ORAI1 in pancreatic acinar cell injury and the development of acute pancreatitis in mice. Methods Mouse and human acinar cells, as well as HEK 293 cells transfected to express human ORAI1 with human stromal interaction molecule 1, were hyperstimulated or incubated with human bile acid, thapsigargin, or cyclopiazonic acid to induce calcium entry. GSK-7975A or CM_128 were added to some cells, which were analyzed by confocal and video microscopy and patch clamp recordings. Acute pancreatitis was induced in C57BL/6J mice by ductal injection of taurolithocholic acid 3-sulfate or intravenous' administration of cerulein or ethanol and palmitoleic acid. Some mice then were given GSK-7975A or CM_128, which inhibit ORAI1, at different time points to assess local and systemic effects. Results GSK-7975A and CM_128 each separately inhibited toxin-induced activation of ORAI1 and/or activation of Ca2+ currents after Ca2+ release, in a concentration-dependent manner, in mouse and human pancreatic acinar cells (inhibition >90% of the levels observed in control cells). The ORAI1 inhibitors also prevented activation of the necrotic cell death pathway in mouse and human pancreatic acinar cells. GSK-7975A and CM_128 each inhibited all local and systemic features of acute pancreatitis in all 3 models, in dose- and time-dependent manners. The agents were significantly more effective, in a range of parameters, when given at 1 vs 6 hours after induction of pancreatitis. Conclusions Cytosolic calcium overload, mediated via ORAI1, contributes to the pathogenesis of acute pancreatitis. ORAI1 inhibitors might be developed

  8. Elucidation of the Roles of the Src kinases in pancreatic acinar cell signaling

    PubMed Central

    Nuche-Berenguer, Bernardo; Moreno, Paola; Jensen, R. T.

    2014-01-01

    Recent studies report the Src-Family kinases(SFK’s) are important in a number of physiological and pathophysiological responses of pancreatic acinar cells(pancreatitis, growth, apoptosis), however, the role of SFKs in various signaling cascades important in mediating these cell functions is either not investigated or unclear. To address this we investigated the action of SFKs in these signaling cascades in rat pancreatic acini by modulating SFK activity using three methods:Adenovirus-induced expression of an inactive dominant-negative CSK(Dn-CSK-Advirus) or Wild-Type CSK(Wt-CSK-Advirus), which activate or inhibit SFK, respectively or using the chemical inhibitor, PP2, with its inactive control, PP3. CCK(0.3,100 nM) and TPA(1 µM) activated SFK and altered the activation of FAK proteins(PYK2, p125 FAK), adaptor proteins(p130CAS, paxillin), MAPK (p42/44, JNK, p38), Shc, PKC(PKD, MARCKS), Akt but not GSK3-β. Changes in SFK activity by using the three methods of altering SFK activity affected CCK/TPAs activation of SFK, PYK2, p125 FAK, p130CAS, Shc, paxillin, Akt but not p42/44, JNK, p38, PKC(PKD, MARCKS) or GSK3-β. With chemical inhibition the active SFK inhibitor, PP2, but not the inactive control analogue, PP3, showed these effects. For all stimulated changes pre-incubation with both adenoviruses showed similar effects to chemical inhibition of SFK activity. In conclusion, using three different approaches to altering Src activity allowed us to define fully for the first time the roles of SFKs in acinar cell signaling. Our results show that in pancreatic acinar cells, SFKs play a much wider role than previously reported in activating a number of important cellular signaling cascades shown to be important in mediating both acinar cell physiological and pathophysiological responses. PMID:25079913

  9. Intracellular mediators of Na -K pump activity in guinea pig pancreatic acinar cells

    SciTech Connect

    Hootman, S.R.; Ochs, D.L.; Williams, J.A.

    1985-10-01

    The involvement of CaS and cyclic nucleotides in neurohormonal regulation of Na -K -ATPase (Na -K pump) activity in guinea pig pancreatic acinar cells was investigated. Changes in Na+-K+ pump activity elicited by secretagogues were assessed by (3H)ouabain binding and by ouabain-sensitive YWRb uptake. Carbachol (CCh) and cholecystokinin octapeptide (CCK-8) each stimulated both ouabain-sensitive 86Rb+ uptake and equilibrium binding of (TH)ouabain by approximately 60%. Secretin increased both indicators of Na+-K+ pump activity by approximately 40% as did forskolin, 8-bromo- and dibutyryl cAMP, theophylline, and isobutylmethylxanthine. Incubation of acinar cells in CaS -free HEPES-buffered Ringer (HR) with 0.5 mM EGTA reduced the stimulatory effects of CCh and CCK-8 by up to 90% but caused only a small reduction in the effects of secretin, forskolin, and cAMP analogues. In addition, CCh, CCK-8, secretin, and forskolin each stimulated ouabain-insensitive 86Rb+ uptake by acinar cells. The increase elicited by CCh and CCK-8 was greatly reduced in the absence of extracellular CaS , while that caused by the latter two agents was not substantially altered. The effects of secretagogues on free CaS levels in pancreatic acinar cells also were investigated with quin-2, a fluorescent CaS chelator. Basal intracellular CaS concentration ((CaS )i) was 161 nM in resting cells and increased to 713 and 803 nM within 15 s after addition of 100 microM CCh or 10 nM CCK-8, respectively.

  10. Calcium signaling of pancreatic acinar cells in the pathogenesis of pancreatitis.

    PubMed

    Li, Jun; Zhou, Rui; Zhang, Jian; Li, Zong-Fang

    2014-11-21

    Pancreatitis is an increasingly common and sometimes severe disease that lacks a specific therapy. The pathogenesis of pancreatitis is still not well understood. Calcium (Ca(2+)) is a versatile carrier of signals regulating many aspects of cellular activity and plays a central role in controlling digestive enzyme secretion in pancreatic acinar cells. Ca(2+) overload is a key early event and is crucial in the pathogenesis of many diseases. In pancreatic acinar cells, pathological Ca(2+) signaling (stimulated by bile, alcohol metabolites and other causes) is a key contributor to the initiation of cell injury due to prolonged and global Ca(2+) elevation that results in trypsin activation, vacuolization and necrosis, all of which are crucial in the development of pancreatitis. Increased release of Ca(2+) from stores in the intracellular endoplasmic reticulum and/or increased Ca(2+) entry through the plasma membrane are causes of such cell damage. Failed mitochondrial adenosine triphosphate (ATP) production reduces re-uptake and extrusion of Ca(2+) by the sarco/endoplasmic reticulum Ca(2+)-activated ATPase and plasma membrane Ca(2+)-ATPase pumps, which contribute to Ca(2+) overload. Current findings have provided further insight into the roles and mechanisms of abnormal pancreatic acinar Ca(2+) signals in pancreatitis. The lack of available specific treatments is therefore an objective of ongoing research. Research is currently underway to establish the mechanisms and interactions of Ca(2+) signals in the pathogenesis of pancreatitis.

  11. Glycosylations in demilunar and central acinar cells of the submandibular salivary gland of ferret investigated by lectin histochemistry.

    PubMed

    Triantafyllou, Asterios; Fletcher, David; Scott, John

    2004-09-01

    'Resting' submandibular salivary glands obtained post-mortem from mature ferrets of both sexes were examined here. The binding patterns of labelled lectins applied to paraffin sections of tissue slivers fixed in an aldehyde-HgCl2 mixture and the effects of pretreatment procedures on the results were assessed lightmicroscopically. Lectins with affinity for terminal GalNAc residues (DBA, SBA) bound preferentially to demilunar acinar cells which were also strongly reactive with Fuc-directed UEA I. In contrast, lectins with affinity for neuraminic acid (SNA, WGA) bound to central acinar cells where consistent binding of DBA and SNA occurred only after neuraminidase digestion, and variation in the binding of UEA I was seen. The reactivities corresponded with the distribution of secretory granules, but staining in Golgi-like areas occurred in central acinar cells with PNA lectin. The results suggest that glycosylations are more advanced in central than demilunar acinar cells of the ferret submandibular gland. Possibly demilunar and central acinar cells reflect phenotypic changes of a single secretory cell, the 'central' acinar phenotype being influenced by incorporation of neuraminic acid in glycoprotein side chains and by increased Golgi activity.

  12. Functional differences in the acinar cells of the murine major salivary glands.

    PubMed

    Kondo, Y; Nakamoto, T; Jaramillo, Y; Choi, S; Catalan, M A; Melvin, J E

    2015-05-01

    In humans, approximately 90% of saliva is secreted by the 3 major salivary glands: the parotid (PG), the submandibular (SMG), and the sublingual glands (SLG). Even though it is known that all 3 major salivary glands secrete saliva by a Cl(-)-dependent mechanism, salivary secretion rates differ greatly among these glands. The goal of this study was to gain insight into the properties of the ion-transporting pathways in acinar cells that might account for the differences among the major salivary glands. Pilocarpine-induced saliva was simultaneously collected in vivo from the 3 major salivary glands of mice. When normalized by gland weight, the amount of saliva secreted by the PG was more than 2-fold larger than that obtained from the SMG and SLG. At the cellular level, carbachol induced an increase in the intracellular [Ca(2+)] that was more than 2-fold larger in PG and SMG than in SLG acinar cells. Carbachol-stimulated Cl(-) efflux and the protein levels of the Ca(2+)-activated Cl(-) channel TMEM16A, the major apical Cl(-) efflux pathway in salivary acinar cells, were significantly greater in PG compared with SMG and SLG. In addition, we evaluated the transporter activity of the Na(+)-K(+)-2Cl(-) cotransporters (NKCC1) and anion exchangers (AE), the 2 primary basolateral Cl(-) uptake mechanisms in acinar cells. The SMG NKCC1 activity was about twice that of the PG and more than 12-fold greater than that of the SLG. AE activity was similar in PG and SLG, and both PG and SLG AE activity was about 2-fold larger than that of SMG. In summary, the salivation kinetics of the 3 major glands are distinct, and these differences can be explained by the unique functional properties of each gland related to Cl(-) movement, including the transporter activities of the Cl(-) uptake and efflux pathways, and intracellular Ca(2+) mobilization.

  13. Confocal and electron microscopy to characterize sialoglycoconjugates in mouse sublingual gland acinar cells.

    PubMed

    Menghi, G; Bondi, A M; Marchetti, L; Ballarini, P; Materazzi, G

    1998-08-01

    Double lectin labeling for confocal microscopy and lectin-protein A-gold binding for electron microscopy were applied to the mouse sublingual gland in order to study surface and cytoplasmic sialoglycoconjugates. For this purpose, serially cut sections were submitted to sialidase followed by incubation with lectins recognizing usually acceptor sugars for terminal sialic acids. At the electron microscope level, the residues subtended to sialic acid were individually identified on adjacent sections by an indirect technique of labeling, whereas with confocal microscopy the above sugars were simultaneously visualized on the same section by a double staining method using fluorescein isothiocyanate (FITC)- and tetramethylrhodamine isothiocyanate (TRITC)-conjugated lectins. Acinar cells were found to contain the terminal sequence sialic acid-beta-galactose in abundance while the sequence sialic acid-alpha-N-acetylgalactosamine appeared to be present in modest amounts. Both sialoglycoconjugates were homogeneously codistributed inside acinar cells. The combination with a saponification method also allowed the occurrence of C4 acetylated sialic acids linked to beta-galactose to be discovered, at the electron microscope level, on acinar cell secretory products.

  14. Inactivation of TGFβ receptor II signalling in pancreatic epithelial cells promotes acinar cell proliferation, acinar-to-ductal metaplasia and fibrosis during pancreatitis.

    PubMed

    Grabliauskaite, Kamile; Saponara, Enrica; Reding, Theresia; Bombardo, Marta; Seleznik, Gitta M; Malagola, Ermanno; Zabel, Anja; Faso, Carmen; Sonda, Sabrina; Graf, Rolf

    2016-02-01

    Determining signalling pathways that regulate pancreatic regeneration following pancreatitis is critical for implementing therapeutic interventions. In this study we elucidated the molecular mechanisms underlying the effects of transforming growth factor-β (TGFβ) in pancreatic epithelial cells during tissue regeneration. To this end, we conditionally inactivated TGFβ receptor II (TGFβ-RII) using a Cre-LoxP system under the control of pancreas transcription factor 1a (PTF1a) promoter, specific for the pancreatic epithelium, and evaluated the molecular and cellular changes in a mouse model of cerulein-induced pancreatitis. We show that TGFβ-RII signalling does not mediate the initial acinar cell damage observed at the onset of pancreatitis. However, TGFβ-RII signalling not only restricts acinar cell replication during the regenerative phase of the disease but also limits ADM formation in vivo and in vitro in a cell-autonomous manner. Analyses of molecular mechanisms underlying the observed phenotype revealed that TGFβ-RII signalling stimulates the expression of cyclin-dependent kinase inhibitors and intersects with the EGFR signalling axis. Finally, TGFβ-RII ablation in epithelial cells resulted in increased infiltration of inflammatory cells in the early phases of pancreatitis and increased activation of pancreatic stellate cells in the later stages of pancreatitis, thus highlighting a TGFβ-based crosstalk between epithelial and stromal cells regulating the development of pancreatic inflammation and fibrosis. Collectively, our data not only contribute to clarifying the cellular processes governing pancreatic tissue regeneration, but also emphasize the conserved role of TGFβ as a tumour suppressor, both in the regenerative process following pancreatitis and in the initial phases of pancreatic cancer.

  15. Inactivation of TGFβ receptor II signalling in pancreatic epithelial cells promotes acinar cell proliferation, acinar-to-ductal metaplasia and fibrosis during pancreatitis.

    PubMed

    Grabliauskaite, Kamile; Saponara, Enrica; Reding, Theresia; Bombardo, Marta; Seleznik, Gitta M; Malagola, Ermanno; Zabel, Anja; Faso, Carmen; Sonda, Sabrina; Graf, Rolf

    2016-02-01

    Determining signalling pathways that regulate pancreatic regeneration following pancreatitis is critical for implementing therapeutic interventions. In this study we elucidated the molecular mechanisms underlying the effects of transforming growth factor-β (TGFβ) in pancreatic epithelial cells during tissue regeneration. To this end, we conditionally inactivated TGFβ receptor II (TGFβ-RII) using a Cre-LoxP system under the control of pancreas transcription factor 1a (PTF1a) promoter, specific for the pancreatic epithelium, and evaluated the molecular and cellular changes in a mouse model of cerulein-induced pancreatitis. We show that TGFβ-RII signalling does not mediate the initial acinar cell damage observed at the onset of pancreatitis. However, TGFβ-RII signalling not only restricts acinar cell replication during the regenerative phase of the disease but also limits ADM formation in vivo and in vitro in a cell-autonomous manner. Analyses of molecular mechanisms underlying the observed phenotype revealed that TGFβ-RII signalling stimulates the expression of cyclin-dependent kinase inhibitors and intersects with the EGFR signalling axis. Finally, TGFβ-RII ablation in epithelial cells resulted in increased infiltration of inflammatory cells in the early phases of pancreatitis and increased activation of pancreatic stellate cells in the later stages of pancreatitis, thus highlighting a TGFβ-based crosstalk between epithelial and stromal cells regulating the development of pancreatic inflammation and fibrosis. Collectively, our data not only contribute to clarifying the cellular processes governing pancreatic tissue regeneration, but also emphasize the conserved role of TGFβ as a tumour suppressor, both in the regenerative process following pancreatitis and in the initial phases of pancreatic cancer. PMID:26510396

  16. Regeneration of acinar cells following ligation of rat submandibular gland retraces the embryonic-perinatal pathway of cytodifferentiation.

    PubMed

    Cotroneo, Emanuele; Proctor, Gordon B; Carpenter, Guy H

    2010-02-01

    Rat submandibular gland can regenerate following ligation-induced atrophy, eventually recovering its normal morphology and function. Previous studies have suggested that the regeneration process implies both self-proliferation of existing acini and formation of new acinar cells. One hypothesis is that new acinar cells may differentiate from the ductal cells in a similar fashion to the process of cytodifferentiation occurring during submandibular glandular development. In this study atrophy was induced, under recovery anaesthesia, by applying a metal clip on the main duct of the submandibular gland without including the chorda lingual nerve. After 2 weeks the duct was deligated for 3, 5 or 7 days or 8 weeks and the glands collected. Tissue was prepared for immunohistochemistry, biochemical analysis and RNA extraction. The histology of the regenerated glands shows several normal-looking acini, which have regained their glycoprotein content (AB/PAS positive), data also confirmed by biochemical analysis (SDS-PAGE/PAS). Regenerating tissue was characterized by the presence of embryonic-like branched structures ending with AB/PAS positive acinar cells. The proteins SMG-B and PSP are normally expressed in acinar cell precursors during development but only by intercalated ductal cells in the adult stage. In the adult regenerating gland mRNA levels of both SMG-B and PSP were found to be up-regulated compared to ligated glands and SMG-B expression localized to acinar cells whilst the ductal cells were negative. This study of rat submandibular gland regeneration suggests new acinar cells have differentiated from ducts and express markers of acinar cell precursors in a similar manner to the cytodifferentiation process occurring during glandular development.

  17. Genetic deletion of Rab27B in pancreatic acinar cells affects granules size and has inhibitory effects on amylase secretion.

    PubMed

    Hou, Yanan; Ernst, Stephen A; Lentz, Stephen I; Williams, John A

    2016-03-18

    Small G protein Rab27B is expressed in various secretory cell types and plays a role in mediating secretion. In pancreatic acinar cells, Rab27B was found to be expressed on the zymogen granule membrane and by overexpression to regulate the secretion of zymogen granules. However, the effect of Rab27B deletion on the physiology of pancreatic acinar cells is unknown. In the current study, we utilized the Rab27B KO mouse model to better understand the role of Rab27B in the secretion of pancreatic acinar cells. Our data show that Rab27B deficiency had no obvious effects on the expression of major digestive enzymes and other closely related proteins, e.g. similar small G proteins, such as Rab3D and Rab27A, and putative downstream effectors. The overall morphology of acinar cells was not changed in the knockout pancreas. However, the size of zymogen granules was decreased in KO acinar cells, suggesting a role of Rab27B in regulating the maturation of secretory granules. The secretion of digestive enzymes was moderately decreased in KO acini, compared with the WT control. These data indicate that Rab27B is involved at a different steps of zymogen granule maturation and secretion, which is distinct from that of Rab3D.

  18. Genetic deletion of Rab27B in pancreatic acinar cells affects granules size and has inhibitory effects on amylase secretion.

    PubMed

    Hou, Yanan; Ernst, Stephen A; Lentz, Stephen I; Williams, John A

    2016-03-18

    Small G protein Rab27B is expressed in various secretory cell types and plays a role in mediating secretion. In pancreatic acinar cells, Rab27B was found to be expressed on the zymogen granule membrane and by overexpression to regulate the secretion of zymogen granules. However, the effect of Rab27B deletion on the physiology of pancreatic acinar cells is unknown. In the current study, we utilized the Rab27B KO mouse model to better understand the role of Rab27B in the secretion of pancreatic acinar cells. Our data show that Rab27B deficiency had no obvious effects on the expression of major digestive enzymes and other closely related proteins, e.g. similar small G proteins, such as Rab3D and Rab27A, and putative downstream effectors. The overall morphology of acinar cells was not changed in the knockout pancreas. However, the size of zymogen granules was decreased in KO acinar cells, suggesting a role of Rab27B in regulating the maturation of secretory granules. The secretion of digestive enzymes was moderately decreased in KO acini, compared with the WT control. These data indicate that Rab27B is involved at a different steps of zymogen granule maturation and secretion, which is distinct from that of Rab3D. PMID:26845357

  19. Cannabinoid receptors in submandibular acinar cells: functional coupling between saliva fluid and electrolytes secretion and Ca2+ signalling.

    PubMed

    Kopach, Olga; Vats, Juliana; Netsyk, Olga; Voitenko, Nana; Irving, Andrew; Fedirko, Nataliya

    2012-04-15

    Cannabinoid receptors (CBRs) belong to the G protein-coupled receptor superfamily, and activation of CBRs in salivary cells inhibits agonist-stimulated salivation and modifies saliva content. However, the role of different CBR subtypes in acinar cell physiology and in intracellular signalling remains unclear. Here, we uncover functional CB(1)Rs and CB(2)Rs in acinar cells of rat submandibular gland and their essential role in saliva secretion. Pharmacological activation of CB(1)Rs and CB(2)Rs in the submandibular gland suppressed saliva outflow and modified saliva content produced by the submandibular gland in vivo. Using Na(+)-selective microelectrodes to record secretory Na(+) responses in the lumen of acini, we observed a reduction in Na(+) transport following the activation of CBRs, which was counteracted by the selective CB(1)R antagonist AM251. In addition, activation of CB(1)Rs or CB Rs caused inhibition of Na(+)-K(+) 2 -ATPase activity in microsomes derived from the gland tissue as well as in isolated acinar cells. Using a Ca(2+) imaging technique, we showed that activation of CB(1)Rs and CB(2)Rs alters [Ca(2+)](cyt) signalling in acinar cells by distinct pathways, involving Ca(2+) release from the endoplasmic reticulum (ER) and store-operated Ca(2+) entry (SOCE), respectively. Our data demonstrate the expression of CB(1)Rs and CB(2)Rs in acinar cells, and their involvement in the regulation of salivary gland functioning.

  20. Up-regulation of Store-operated Ca2+ Entry and Nuclear Factor of Activated T Cells Promote the Acinar Phenotype of the Primary Human Salivary Gland Cells.

    PubMed

    Jang, Shyh-Ing; Ong, Hwei Ling; Liu, Xibao; Alevizos, Ilias; Ambudkar, Indu S

    2016-04-15

    The signaling pathways involved in the generation and maintenance of exocrine gland acinar cells have not yet been established. Primary human salivary gland epithelial cells, derived from salivary gland biopsies, acquired an acinar-like phenotype when the [Ca(2+)] in the serum-free medium (keratinocyte growth medium, KGM) was increased from 0.05 mm (KGM-L) to 1.2 mm (KGM-H). Here we examined the mechanism underlying this Ca(2+)-dependent generation of the acinar cell phenotype. Compared with cells in KGM-L, those in KGM-H display enhancement of Orai1, STIM1, STIM2, and nuclear factor of activated T cells 1 (NFAT1) expression together with an increase in store-operated Ca(2+) entry (SOCE), SOCE-dependent nuclear translocation of pGFP-NFAT1, and NFAT-dependent but not NFκB-dependent gene expression. Importantly, AQP5, an acinar-specific protein critical for function, is up-regulated in KGM-H via SOCE/NFAT-dependent gene expression. We identified critical NFAT binding motifs in the AQP5 promoter that are involved in Ca(2+)-dependent up-regulation of AQP5. These important findings reveal that the Ca(2+)-induced switch of salivary epithelial cells to an acinar-like phenotype involves remodeling of SOCE and NFAT signaling, which together control the expression of proteins critically relevant for acinar cell function. Our data provide a novel strategy for generating and maintaining acinar cells in culture.

  1. Salivary gland acinar cells regenerate functional glandular structures in modified hydrogels

    NASA Astrophysics Data System (ADS)

    Pradhan, Swati

    Xerostomia, a condition resulting from irradiation of the head and neck, affects over 40,000 cancer patients each year in the United States. Direct radiation damage of the acinar cells that secrete fluid and protein results in salivary gland hypofunction. Present medical management for xerostomia for patients treated for upper respiratory cancer is largely ineffective. Patients who have survived their terminal diagnosis are often left with a diminished quality of life and are unable to enjoy the simple pleasures of eating and drinking. This project aims to ultimately reduce human suffering by developing a functional implantable artificial salivary gland. The goal was to create an extracellular matrix (ECM) modified hyaluronic acid (HA) based hydrogel culture system that allows for the growth and differentiation of salivary acinar cells into functional acini-like structures capable of secreting large amounts of protein and fluid unidirectionally and to ultimately engineer a functional artificial salivary gland that can be implanted into an animal model. A tissue collection protocol was established and salivary gland tissue was obtained from patients undergoing head and neck surgery. The tissue specimen was assessed by histology and immunohistochemistry to establish the phenotype of normal salivary gland cells including the native basement membranes. Hematoxylin and eosin staining confirmed normal glandular tissue structures including intercalated ducts, striated ducts and acini. alpha-Amylase and periodic acid schiff stain, used for structures with a high proportion of carbohydrate macromolecules, preferentially stained acinar cells in the tissue. Intercalated and striated duct structures were identified using cytokeratins 19 and 7 staining. Myoepithelial cells positive for cytokeratin 14 were found wrapped around the serous and mucous acini. Tight junction components including ZO-1 and E-cadherin were present between both ductal and acinar cells. Ductal and acinar

  2. Antigen-presenting cells in parotid glands contain cystatin D originating from acinar cells.

    PubMed

    Nashida, Tomoko; Sato, Ritsuko; Haga-Tsujimura, Maiko; Yoshie, Sumio; Yoshimura, Ken; Imai, Akane; Shimomura, Hiromi

    2013-02-01

    Cystatin D encoded by Cst5 is a salivary classified type II cystatin. We investigated the dynamism of cystatin D by examining the distribution of cystatin D protein and mRNA in rats, to identify novel functions. The simultaneous expression of Cst5 and cystatin D was observed in parotid glands, however in situ hybridization showed that only acinar cells produced cystatin D. Synthesized cystatin D was localized in small vesicles and secreted from the apical side to the saliva, and from the basolateral side to the extracellular region, a second secretory pathway for cystatin D. We also identified antigen-presenting cells in the parotid glands that contained cystatin D without the expression of Cst5, indicating the uptake of cystatin D from the extracellular region. Cystatin D was detected in blood serum and renal tubular cells with megalin, indicating the circulation of cystatin D through the body and uptake by renal tubular cells. Thus, the novel dynamism of cystatin D was shown and a function for cystatin D in the regulation of antigen-presenting cell activity was proposed.

  3. Polycomb repressor complex 1 promotes gene silencing through H2AK119 mono-ubiquitination in acinar-to-ductal metaplasia and pancreatic cancer cells

    PubMed Central

    Reinhard, Tobias; Popp, Anna; Schäffer, Isabell; Raulefs, Susanne; Kong, Bo; Esposito, Irene

    2016-01-01

    Acinar-to-ductal metaplasia (ADM) occurring in cerulein-mediated pancreatitis or in oncogenic Kras-driven pancreatic cancer development is accompanied by extensive changes in the transcriptional program. In this process, acinar cells shut down the expression of acinar specific differentiation genes and re-express genes usually found in embryonic pancreatic progenitor cells. Previous studies have demonstrated that a loss of acinar-specific transcription factors sensitizes the cells towards oncogenic transformation, ultimately resulting in cancer development. However, the mechanism behind the transcriptional silencing of acinar cell fate genes in ADM and pancreatic cancer is largely unknown. Here, we analyzed whether elevated levels of the polycomb repressor complex 1 (PRC1) components Bmi1 and Ring1b and their catalyzed histone modification H2AK119ub in ADMs and tumor cells, are responsible for the mediation of acinar gene silencing. Therefore, we performed chromatin-immunoprecipitation in in vitro generated ADMs and isolated murine tumor cells against the repressive histone modifications H3K27me3 and H2AK119ub. We established that the acinar transcription factor complex Ptf1-L is epigenetically silenced in ADMs as well as in pancreatic tumor cells. For the first time, this work presents a possible mechanism of acinar gene silencing, which is an important prerequisite in the initiation and maintenance of a dedifferentiated cell state in ADMs and tumor cells. PMID:26716510

  4. THE DEGENERATIVE CHANGES IN PANCREATIC ACINAR CELLS CAUSED BY DL-ETHIONINE

    PubMed Central

    Herman, Lawrence; Fitzgerald, Patrick J.

    1962-01-01

    Degeneration of pancreatic acinar cells in rats injected with ethionine was studied by electron microscopy. The most conspicuous morphologic lesions occurred in the ergastoplasm. There was a widening of the endoplasmic reticulum, a decrease in number of membrane-associated ribosomes, and a development of fine and coarse vacuoles containing agranular disoriented membranes. Cytoplasmic ribosomes unassociated with membranes were less numerous. Nuclear changes consisted of a coarsening and clumping of the nuclear chromatin, chromatin margination, and increased osmiophilia and vacuolation of the nucleolus. Eight to ten days after the beginning of ethionine injections, changes in zymogen granules, mitochondria, and the Golgi apparatus appeared, but only after extensive damage to the acinar cell. The effects were consistent with ethionine's known interference with protein metabolism but also suggest disturbance in ribonucleic acid metabolism. The ergastoplasmic changes after ethionine were similar in some respects to the early lesions produced in liver parenchymal cells by fasting, to the changes occurring in animals on protein-free diets, or to some of the liver changes produced by azo dye carcinogens. The ribosomal and ergastoplasmic changes represent early morphologic expressions of the biochemical effect of ethionine. PMID:13906694

  5. MHC class II molecules, cathepsins, and La/SSB proteins in lacrimal acinar cell endomembranes.

    PubMed

    Yang, T; Zeng, H; Zhang, J; Okamoto, C T; Warren, D W; Wood, R L; Bachmann, M; Mircheff, A K

    1999-11-01

    Sjögren's syndrome is a chronic autoimmune disease affecting the lacrimal glands and other epithelia. It has been suggested that acinar cells of the lacrimal glands provoke local autoimmune responses, leading to Sjögren's syndrome when they begin expressing major histocompatibility complex (MHC) class II molecules. We used isopycnic centrifugation and phase partitioning to resolve compartments that participate in traffic between the basolateral membranes and the endomembrane system to test the hypothesis that MHC class II molecules enter compartments that contain potential autoantigens, i.e., La/SSB, and enzymes capable of proteolytically processing autoantigen, i.e., cathepsins B and D. A series of compartments identified as secretory vesicle membranes, prelysosomes, and microdomains of the trans-Golgi network involved in traffic to the basolateral membrane, to the secretory vesicles, and to the prelysosomes were all prominent loci of MHC class II molecules, La/SSB, and cathepsins B and D. These observations support the thesis that lacrimal gland acinar cells that have been induced to express MHC class II molecules function as autoantigen processing and presenting cells.

  6. A tetanus toxin sensitive protein other than VAMP 2 is required for exocytosis in the pancreatic acinar cell.

    PubMed

    Padfield, P J

    2000-11-01

    The neurotoxin sensitivity of regulated exocytosis in the pancreatic acinar cell was investigated using streptolysin-O permeabilized pancreatic acini. Treatment of permeabilized acini with botulinum toxin B (BoNT/B) or botulinum toxin D (BoNT/D) had no detectable effect on Ca(2+)-dependent amylase secretion but did result in the complete cleavage of VAMP 2. In comparison, tetanus toxin (TeTx) treatment both significantly inhibited Ca(2+)-dependent amylase secretion and cleaved VAMP 2. These results indicate that regulated exocytosis in the pancreatic acinar cell requires a tetanus toxin sensitive protein(s) other than VAMP 2.

  7. Activation of neurokinin-1 receptors up-regulates substance P and neurokinin-1 receptor expression in murine pancreatic acinar cells.

    PubMed

    Koh, Yung-Hua; Moochhala, Shabbir; Bhatia, Madhav

    2012-07-01

    Acute pancreatitis (AP) has been associated with an up-regulation of substance P (SP) and neurokinin-1 receptor (NK1R) in the pancreas. Increased SP-NK1R interaction was suggested to be pro-inflammatory during AP. Previously, we showed that caerulein treatment increased SP/NK1R expression in mouse pancreatic acinar cells, but the effect of SP treatment was not evaluated. Pancreatic acinar cells were obtained from pancreas of male swiss mice (25-30 g). We measured mRNA expression of preprotachykinin-A (PPTA) and NK1R following treatment of SP (10(-6) M). SP treatment increased PPTA and NK1R expression in isolated pancreatic acinar cells, which was abolished by pretreatment of a selective NK1R antagonist, CP96,345. SP also time dependently increased protein expression of NK1R. Treatment of cells with a specific NK1R agonist, GR73,632, up-regulated SP protein levels in the cells. Using previously established concentrations, pre-treatment of pancreatic acinar cells with Gö6976 (10 nM), rottlerin (5 μM), PD98059 (30 μM), SP600125 (30 μM) or Bay11-7082 (30 μM) significantly inhibited up-regulation of SP and NK1R. These observations suggested that the PKC-ERK/JNK-NF-κB pathway is necessary for the modulation of expression levels. In comparison, pre-treatment of CP96,345 reversed gene expression in SP-induced cells, but not in caerulein-treated cells. Overall, the findings in this study suggested a possible auto-regulatory mechanism of SP/NK1R expression in mouse pancreatic acinar cells, via activation of NK1R. Elevated SP levels during AP might increase the occurrence of a positive feedback loop that contributes to abnormally high expression of SP and NK1R.

  8. Activation of neurokinin-1 receptors up-regulates substance P and neurokinin-1 receptor expression in murine pancreatic acinar cells

    PubMed Central

    Koh, Yung-Hua; Moochhala, Shabbir; Bhatia, Madhav

    2012-01-01

    Abstract Acute pancreatitis (AP) has been associated with an up-regulation of substance P (SP) and neurokinin-1 receptor (NK1R) in the pancreas. Increased SP-NK1R interaction was suggested to be pro-inflammatory during AP. Previously, we showed that caerulein treatment increased SP/NK1R expression in mouse pancreatic acinar cells, but the effect of SP treatment was not evaluated. Pancreatic acinar cells were obtained from pancreas of male swiss mice (25–30 g). We measured mRNA expression of preprotachykinin-A (PPTA) and NK1R following treatment of SP (10−6M). SP treatment increased PPTA and NK1R expression in isolated pancreatic acinar cells, which was abolished by pretreatment of a selective NK1R antagonist, CP96,345. SP also time dependently increased protein expression of NK1R. Treatment of cells with a specific NK1R agonist, GR73,632, up-regulated SP protein levels in the cells. Using previously established concentrations, pre-treatment of pancreatic acinar cells with Gö6976 (10 nM), rottlerin (5 μM), PD98059 (30 μM), SP600125 (30 μM) or Bay11-7082 (30 μM) significantly inhibited up-regulation of SP and NK1R. These observations suggested that the PKC-ERK/JNK-NF-κB pathway is necessary for the modulation of expression levels. In comparison, pre-treatment of CP96,345 reversed gene expression in SP-induced cells, but not in caerulein-treated cells. Overall, the findings in this study suggested a possible auto-regulatory mechanism of SP/NK1R expression in mouse pancreatic acinar cells, via activation of NK1R. Elevated SP levels during AP might increase the occurrence of a positive feedback loop that contributes to abnormally high expression of SP and NK1R. PMID:22040127

  9. Glucagon-like peptide-1 receptor is present in pancreatic acinar cells and regulates amylase secretion through cAMP.

    PubMed

    Hou, Yanan; Ernst, Stephen A; Heidenreich, Kaeli; Williams, John A

    2016-01-01

    Glucagon-like peptide-1 (GLP-1) is a glucoincretin hormone that can act through its receptor (GLP-1R) on pancreatic β-cells and increase insulin secretion and production. GLP-1R agonists are used clinically to treat type 2 diabetes. GLP-1 may also regulate the exocrine pancreas at multiple levels, including inhibition through the central nervous system, stimulation indirectly through insulin, and stimulation directly on acinar cells. However, it has been unclear whether GLP-1R is present in pancreatic acini and what physiological functions these receptors regulate. In the current study we utilized GLP-1R knockout (KO) mice to study the role of GLP-1R in acinar cells. RNA expression of GLP-1R was detected in acutely isolated pancreatic acini. Acinar cell morphology and expression of digestive enzymes were not affected by loss of GLP-1R. GLP-1 induced amylase secretion in wild-type (WT) acini. In GLP-1R KO mice, this effect was abolished, whereas vasoactive intestinal peptide-induced amylase release in KO acini showed a pattern similar to that in WT acini. GLP-1 stimulated cAMP production and increased protein kinase A-mediated protein phosphorylation in WT acini, and these effects were absent in KO acini. These data show that GLP-1R is present in pancreatic acinar cells and that GLP-1 can regulate secretion through its receptor and cAMP signaling pathway.

  10. A Systems Biology Approach Identifies a Regulatory Network in Parotid Acinar Cell Terminal Differentiation

    PubMed Central

    Metzler, Melissa A.; Venkatesh, Srirangapatnam G.; Lakshmanan, Jaganathan; Carenbauer, Anne L.; Perez, Sara M.; Andres, Sarah A.; Appana, Savitri; Brock, Guy N.; Wittliff, James L.; Darling, Douglas S.

    2015-01-01

    Objective The transcription factor networks that drive parotid salivary gland progenitor cells to terminally differentiate, remain largely unknown and are vital to understanding the regeneration process. Methodology A systems biology approach was taken to measure mRNA and microRNA expression in vivo across acinar cell terminal differentiation in the rat parotid salivary gland. Laser capture microdissection (LCM) was used to specifically isolate acinar cell RNA at times spanning the month-long period of parotid differentiation. Results Clustering of microarray measurements suggests that expression occurs in four stages. mRNA expression patterns suggest a novel role for Pparg which is transiently increased during mid postnatal differentiation in concert with several target gene mRNAs. 79 microRNAs are significantly differentially expressed across time. Profiles of statistically significant changes of mRNA expression, combined with reciprocal correlations of microRNAs and their target mRNAs, suggest a putative network involving Klf4, a differentiation inhibiting transcription factor, which decreases as several targeting microRNAs increase late in differentiation. The network suggests a molecular switch (involving Prdm1, Sox11, Pax5, miR-200a, and miR-30a) progressively decreases repression of Xbp1 gene transcription, in concert with decreased translational repression by miR-214. The transcription factor Xbp1 mRNA is initially low, increases progressively, and may be maintained by a positive feedback loop with Atf6. Transfection studies show that Xbp1Mist1 promoter. In addition, Xbp1 and Mist1 each activate the parotid secretory protein (Psp) gene, which encodes an abundant salivary protein, and is a marker of terminal differentiation. Conclusion This study identifies novel expression patterns of Pparg, Klf4, and Sox11 during parotid acinar cell differentiation, as well as numerous differentially expressed microRNAs. Network analysis identifies a novel stemness arm, a

  11. Tmem16A encodes the Ca2+-activated Cl- channel in mouse submandibular salivary gland acinar cells.

    PubMed

    Romanenko, Victor G; Catalán, Marcelo A; Brown, David A; Putzier, Ilva; Hartzell, H Criss; Marmorstein, Alan D; Gonzalez-Begne, Mireya; Rock, Jason R; Harfe, Brian D; Melvin, James E

    2010-04-23

    Activation of an apical Ca(2+)-dependent Cl(-) channel (CaCC) is the rate-limiting step for fluid secretion in many exocrine tissues. Here, we compared the properties of native CaCC in mouse submandibular salivary gland acinar cells to the Ca(2+)-gated Cl(-) currents generated by Tmem16A and Best2, members from two distinct families of Ca(2+)-activated Cl(-) channels found in salivary glands. Heterologous expression of Tmem16A and Best2 transcripts in HEK293 cells produced Ca(2+)-activated Cl(-) currents with time and voltage dependence and inhibitor sensitivity that resembled the Ca(2+)-activated Cl(-) current found in native salivary acinar cells. Best2(-/-) and Tmem16A(-/-) mice were used to further characterize the role of these channels in the exocrine salivary gland. The amplitude and the biophysical footprint of the Ca(2+)-activated Cl(-) current in submandibular gland acinar cells from Best2-deficient mice were the same as in wild type cells. Consistent with this observation, the fluid secretion rate in Best2 null mice was comparable with that in wild type mice. In contrast, submandibular gland acinar cells from Tmem16A(-/-) mice lacked a Ca(2+)-activated Cl(-) current and a Ca(2+)-mobilizing agonist failed to stimulate Cl(-) efflux, requirements for fluid secretion. Furthermore, saliva secretion was abolished by the CaCC inhibitor niflumic acid in wild type and Best2(-/-) mice. Our results demonstrate that both Tmem16A and Best2 generate Ca(2+)-activated Cl(-) current in vitro with similar properties to those expressed in native cells, yet only Tmem16A appears to be a critical component of the acinar Ca(2+)-activated Cl(-) channel complex that is essential for saliva production by the submandibular gland.

  12. Cleavage of SNAP-25 and VAMP-2 impairs store-operated Ca2+ entry in mouse pancreatic acinar cells.

    PubMed

    Rosado, Juan A; Redondo, Pedro C; Salido, Ginés M; Sage, Stewart O; Pariente, Jose A

    2005-01-01

    We recently reported that store-operated Ca(2+) entry (SOCE) in nonexcitable cells is likely to be mediated by a reversible interaction between Ca(2+) channels in the plasma membrane and the endoplasmic reticulum, a mechanism known as "secretion-like coupling." As for secretion, in this model the actin cytoskeleton plays a key regulatory role. In the present study we have explored the involvement of the secretory proteins synaptosome-associated protein (SNAP-25) and vesicle-associated membrane protein (VAMP) in SOCE in pancreatic acinar cells. Cleavage of SNAP-25 and VAMPs by treatment with botulinum toxin A (BoNT A) and tetanus toxin (TeTx), respectively, effectively inhibited amylase secretion stimulated by the physiological agonist CCK-8. BoNT A significantly reduced Ca(2+) entry induced by store depletion using thapsigargin or CCK-8. In addition, treatment with BoNT A once SOCE had been activated reduced Ca(2+) influx, indicating that SNAP-25 is needed for both the activation and maintenance of SOCE in pancreatic acinar cells. VAMP-2 and VAMP-3 are expressed in mouse pancreatic acinar cells. Both proteins associate with the cytoskeleton upon Ca(2+) store depletion, although only VAMP-2 seems to be sensitive to TeTx. Treatment of pancreatic acinar cells with TeTx reduced the activation of SOCE without affecting its maintenance. These findings support a role for SNAP-25 and VAMP-2 in the activation of SOCE in pancreatic acinar cells and show parallels between this process and secretion in a specialized secretory cell type.

  13. Programmed cell death

    SciTech Connect

    1995-12-31

    The purpose of this conference to provide a multidisciplinary forum for exchange of state-of-the-art information on the role programmed cell death plays in normal development and homeostasis of many organisms. This volume contains abstracts of papers in the following areas: invertebrate development; immunology/neurology; bcl-2 family; biochemistry; programmed cell death in viruses; oncogenesis; vertebrate development; and diseases.

  14. Variations in the expression and distribution pattern of AQP5 in acinar cells of patients with sialadenosis.

    PubMed

    Teymoortash, Afshin; Wiegand, Susanne; Borkeloh, Martin; Bette, Michael; Ramaswamy, Annette; Steinbach-Hundt, Silke; Neff, Andreas; Werner, Jochen A; Mandic, Robert

    2012-01-01

    Previously, we pointed out on a possible role of aquaporin 5 (AQP5) in the development of sialadenosis. The goal of the present study was to further assess the association of AQP5 in the development of this salivary gland disease. The acinar diameter and mean surface area appeared elevated in sialadenosis tissues, which is a typical observation in this disease. AQP5 expression was evaluated by immunohistochemistry using tissue samples derived from salivary glands of patients with confirmed sialadenosis either as a primary diagnosis or as a secondary diagnosis within the framework of other salivary gland diseases. Normal salivary gland tissue served as a control. In sialadenosis tissues, the AQP5 signal at the apical plasma membrane of acinar cells frequently appeared stronger compared with that in normal salivary glands. In addition, the distribution of AQP5 at the apical region seemed to differ between normal and sialadenosis tissues, where AQP5 frequently was diffusely distributed near or at the apical plasma membrane of the acinar cells in contrast to normal controls where the AQP5 signal was strictly confined to the apical plasma membrane. These observations suggest that sialadenosis is associated with a different AQP5 expression and distribution pattern in salivary acinar cells.

  15. Cannabinoid receptor subtype 2 (CB2R) agonist, GW405833 reduces agonist-induced Ca(2+) oscillations in mouse pancreatic acinar cells.

    PubMed

    Huang, Zebing; Wang, Haiyan; Wang, Jingke; Zhao, Mengqin; Sun, Nana; Sun, Fangfang; Shen, Jianxin; Zhang, Haiying; Xia, Kunkun; Chen, Dejie; Gao, Ming; Hammer, Ronald P; Liu, Qingrong; Xi, Zhengxiong; Fan, Xuegong; Wu, Jie

    2016-01-01

    Emerging evidence demonstrates that the blockade of intracellular Ca(2+) signals may protect pancreatic acinar cells against Ca(2+) overload, intracellular protease activation, and necrosis. The activation of cannabinoid receptor subtype 2 (CB2R) prevents acinar cell pathogenesis in animal models of acute pancreatitis. However, whether CB2Rs modulate intracellular Ca(2+) signals in pancreatic acinar cells is largely unknown. We evaluated the roles of CB2R agonist, GW405833 (GW) in agonist-induced Ca(2+) oscillations in pancreatic acinar cells using multiple experimental approaches with acute dissociated pancreatic acinar cells prepared from wild type, CB1R-knockout (KO), and CB2R-KO mice. Immunohistochemical labeling revealed that CB2R protein was expressed in mouse pancreatic acinar cells. Electrophysiological experiments showed that activation of CB2Rs by GW reduced acetylcholine (ACh)-, but not cholecystokinin (CCK)-induced Ca(2+) oscillations in a concentration-dependent manner; this inhibition was prevented by a selective CB2R antagonist, AM630, or was absent in CB2R-KO but not CB1R-KO mice. In addition, GW eliminated L-arginine-induced enhancement of Ca(2+) oscillations, pancreatic amylase, and pulmonary myeloperoxidase. Collectively, we provide novel evidence that activation of CB2Rs eliminates ACh-induced Ca(2+) oscillations and L-arginine-induced enhancement of Ca(2+) signaling in mouse pancreatic acinar cells, which suggests a potential cellular mechanism of CB2R-mediated protection in acute pancreatitis. PMID:27432473

  16. Cannabinoid receptor subtype 2 (CB2R) agonist, GW405833 reduces agonist-induced Ca2+ oscillations in mouse pancreatic acinar cells

    PubMed Central

    Huang, Zebing; Wang, Haiyan; Wang, Jingke; Zhao, Mengqin; Sun, Nana; Sun, Fangfang; Shen, Jianxin; Zhang, Haiying; Xia, Kunkun; Chen, Dejie; Gao, Ming; Hammer, Ronald P.; Liu, Qingrong; Xi, Zhengxiong; Fan, Xuegong; Wu, Jie

    2016-01-01

    Emerging evidence demonstrates that the blockade of intracellular Ca2+ signals may protect pancreatic acinar cells against Ca2+ overload, intracellular protease activation, and necrosis. The activation of cannabinoid receptor subtype 2 (CB2R) prevents acinar cell pathogenesis in animal models of acute pancreatitis. However, whether CB2Rs modulate intracellular Ca2+ signals in pancreatic acinar cells is largely unknown. We evaluated the roles of CB2R agonist, GW405833 (GW) in agonist-induced Ca2+ oscillations in pancreatic acinar cells using multiple experimental approaches with acute dissociated pancreatic acinar cells prepared from wild type, CB1R-knockout (KO), and CB2R-KO mice. Immunohistochemical labeling revealed that CB2R protein was expressed in mouse pancreatic acinar cells. Electrophysiological experiments showed that activation of CB2Rs by GW reduced acetylcholine (ACh)-, but not cholecystokinin (CCK)-induced Ca2+ oscillations in a concentration-dependent manner; this inhibition was prevented by a selective CB2R antagonist, AM630, or was absent in CB2R-KO but not CB1R-KO mice. In addition, GW eliminated L-arginine-induced enhancement of Ca2+ oscillations, pancreatic amylase, and pulmonary myeloperoxidase. Collectively, we provide novel evidence that activation of CB2Rs eliminates ACh-induced Ca2+ oscillations and L-arginine-induced enhancement of Ca2+ signaling in mouse pancreatic acinar cells, which suggests a potential cellular mechanism of CB2R-mediated protection in acute pancreatitis. PMID:27432473

  17. Chronic alcohol exposure inhibits biotin uptake by pancreatic acinar cells: possible involvement of epigenetic mechanisms.

    PubMed

    Srinivasan, Padmanabhan; Kapadia, Rubina; Biswas, Arundhati; Said, Hamid M

    2014-11-01

    Chronic exposure to alcohol affects different physiological aspects of pancreatic acinar cells (PAC), but its effect on the uptake process of biotin is not known. We addressed this issue using mouse-derived pancreatic acinar 266-6 cells chronically exposed to alcohol and wild-type and transgenic mice (carrying the human SLC5A6 5'-promoter) fed alcohol chronically. First we established that biotin uptake by PAC is Na(+) dependent and carrier mediated and involves sodium-dependent multivitamin transporter (SMVT). Chronic exposure of 266-6 cells to alcohol led to a significant inhibition in biotin uptake, expression of SMVT protein, and mRNA as well as in the activity of the SLC5A6 promoter. Similarly, chronic alcohol feeding of wild-type and transgenic mice carrying the SLC5A6 promoter led to a significant inhibition in biotin uptake by PAC, as well as in the expression of SMVT protein and mRNA and the activity of the SLC5A6 promoters expressed in the transgenic mice. We also found that chronic alcohol feeding of mice is associated with a significant increase in the methylation status of CpG islands predicted to be in the mouse Slc5a6 promoters and a decrease in the level of expression of transcription factor KLF-4, which plays an important role in regulating SLC5A6 promoter activity. These results demonstrate, for the first time, that chronic alcohol exposure negatively impacts biotin uptake in PAC and that this effect is exerted (at least in part) at the level of transcription of the SLC5A6 gene and may involve epigenetic/molecular mechanisms.

  18. Ascl3 expression marks a progenitor population of both acinar and ductal cells in mouse salivary glands.

    PubMed

    Bullard, Tara; Koek, Laurie; Roztocil, Elisa; Kingsley, Paul D; Mirels, Lily; Ovitt, Catherine E

    2008-08-01

    Ascl3, also know as Sgn1, is a member of the mammalian achaete scute (Mash) gene family of transcription factors, which have been implicated in cell fate specification and differentiation. In the mouse salivary gland, expression of Ascl3 is restricted to a subset of duct cells. Salivary gland function depends on the secretory acinar cells, which are responsible for saliva formation, and duct cells, which modify the saliva and conduct it to the oral cavity. The salivary gland ducts are also the putative site of progenitor cells in the adult gland. Using a Cre recombinase-mediated reporter system, we followed the fate of Ascl3-expressing cells after the introduction of an EGFP-Cre expression cassette into the Ascl3 locus by homologous recombination. Lineage tracing shows that these cells are progenitors of both acinar and ductal cell types in all three major salivary glands. In the differentiated progeny, expression of Ascl3 is down-regulated. These data directly demonstrate a progenitor-progeny relationship between duct cells and the acinar cell compartment, and identify a population of multipotent progenitor cells, marked by expression of Ascl3, which is capable of generating both gland cell types. We conclude that Ascl3-expressing cells contribute to the maintenance of the adult salivary glands.

  19. The Acinar Cage: Basement Membranes Determine Molecule Exchange and Mechanical Stability of Human Breast Cell Acini.

    PubMed

    Gaiko-Shcherbak, Aljona; Fabris, Gloria; Dreissen, Georg; Merkel, Rudolf; Hoffmann, Bernd; Noetzel, Erik

    2015-01-01

    The biophysical properties of the basement membrane that surrounds human breast glands are poorly understood, but are thought to be decisive for normal organ function and malignancy. Here, we characterize the breast gland basement membrane with a focus on molecule permeation and mechanical stability, both crucial for organ function. We used well-established and nature-mimicking MCF10A acini as 3D cell model for human breast glands, with ether low- or highly-developed basement membrane scaffolds. Semi-quantitative dextran tracer (3 to 40 kDa) experiments allowed us to investigate the basement membrane scaffold as a molecule diffusion barrier in human breast acini in vitro. We demonstrated that molecule permeation correlated positively with macromolecule size and intriguingly also with basement membrane development state, revealing a pore size of at least 9 nm. Notably, an intact collagen IV mesh proved to be essential for this permeation function. Furthermore, we performed ultra-sensitive atomic force microscopy to quantify the response of native breast acini and of decellularized basement membrane shells against mechanical indentation. We found a clear correlation between increasing acinar force resistance and basement membrane formation stage. Most important native acini with highly-developed basement membranes as well as cell-free basement membrane shells could both withstand physiologically relevant loads (≤ 20 nN) without loss of structural integrity. In contrast, low-developed basement membranes were significantly softer and more fragile. In conclusion, our study emphasizes the key role of the basement membrane as conductor of acinar molecule influx and mechanical stability of human breast glands, which are fundamental for normal organ function.

  20. The Acinar Cage: Basement Membranes Determine Molecule Exchange and Mechanical Stability of Human Breast Cell Acini

    PubMed Central

    Gaiko-Shcherbak, Aljona; Fabris, Gloria; Dreissen, Georg; Merkel, Rudolf; Hoffmann, Bernd; Noetzel, Erik

    2015-01-01

    The biophysical properties of the basement membrane that surrounds human breast glands are poorly understood, but are thought to be decisive for normal organ function and malignancy. Here, we characterize the breast gland basement membrane with a focus on molecule permeation and mechanical stability, both crucial for organ function. We used well-established and nature-mimicking MCF10A acini as 3D cell model for human breast glands, with ether low- or highly-developed basement membrane scaffolds. Semi-quantitative dextran tracer (3 to 40 kDa) experiments allowed us to investigate the basement membrane scaffold as a molecule diffusion barrier in human breast acini in vitro. We demonstrated that molecule permeation correlated positively with macromolecule size and intriguingly also with basement membrane development state, revealing a pore size of at least 9 nm. Notably, an intact collagen IV mesh proved to be essential for this permeation function. Furthermore, we performed ultra-sensitive atomic force microscopy to quantify the response of native breast acini and of decellularized basement membrane shells against mechanical indentation. We found a clear correlation between increasing acinar force resistance and basement membrane formation stage. Most important native acini with highly-developed basement membranes as well as cell-free basement membrane shells could both withstand physiologically relevant loads (≤ 20 nN) without loss of structural integrity. In contrast, low-developed basement membranes were significantly softer and more fragile. In conclusion, our study emphasizes the key role of the basement membrane as conductor of acinar molecule influx and mechanical stability of human breast glands, which are fundamental for normal organ function. PMID:26674091

  1. The Acinar Cage: Basement Membranes Determine Molecule Exchange and Mechanical Stability of Human Breast Cell Acini.

    PubMed

    Gaiko-Shcherbak, Aljona; Fabris, Gloria; Dreissen, Georg; Merkel, Rudolf; Hoffmann, Bernd; Noetzel, Erik

    2015-01-01

    The biophysical properties of the basement membrane that surrounds human breast glands are poorly understood, but are thought to be decisive for normal organ function and malignancy. Here, we characterize the breast gland basement membrane with a focus on molecule permeation and mechanical stability, both crucial for organ function. We used well-established and nature-mimicking MCF10A acini as 3D cell model for human breast glands, with ether low- or highly-developed basement membrane scaffolds. Semi-quantitative dextran tracer (3 to 40 kDa) experiments allowed us to investigate the basement membrane scaffold as a molecule diffusion barrier in human breast acini in vitro. We demonstrated that molecule permeation correlated positively with macromolecule size and intriguingly also with basement membrane development state, revealing a pore size of at least 9 nm. Notably, an intact collagen IV mesh proved to be essential for this permeation function. Furthermore, we performed ultra-sensitive atomic force microscopy to quantify the response of native breast acini and of decellularized basement membrane shells against mechanical indentation. We found a clear correlation between increasing acinar force resistance and basement membrane formation stage. Most important native acini with highly-developed basement membranes as well as cell-free basement membrane shells could both withstand physiologically relevant loads (≤ 20 nN) without loss of structural integrity. In contrast, low-developed basement membranes were significantly softer and more fragile. In conclusion, our study emphasizes the key role of the basement membrane as conductor of acinar molecule influx and mechanical stability of human breast glands, which are fundamental for normal organ function. PMID:26674091

  2. Autophagic cell death exists

    PubMed Central

    Clarke, Peter G.H.; Puyal, Julien

    2012-01-01

    The term autophagic cell death (ACD) initially referred to cell death with greatly enhanced autophagy, but is increasingly used to imply a death-mediating role of autophagy, as shown by a protective effect of autophagy inhibition. In addition, many authors require that autophagic cell death must not involve apoptosis or necrosis. Adopting these new and restrictive criteria, and emphasizing their own failure to protect human osteosarcoma cells by autophagy inhibition, the authors of a recent Editor’s Corner article in this journal argued for the extreme rarity or nonexistence of autophagic cell death. We here maintain that, even with the more stringent recent criteria, autophagic cell death exists in several situations, some of which were ignored by the Editor’s Corner authors. We reject their additional criterion that the autophagy in ACD must be the agent of ultimate cell dismantlement. And we argue that rapidly dividing mammalian cells such as cancer cells are not the most likely situation for finding pure ACD. PMID:22652592

  3. Classification of cell death

    PubMed Central

    Kroemer, G; Galluzzi, L; Vandenabeele, P; Abrams, J; Alnemri, ES; Baehrecke, EH; Blagosklonny, MV; El-Deiry, WS; Golstein, P; Green, DR; Hengartner, M; Knight, RA; Kumar, S; Lipton, SA; Malorni, W; Nuñez, G; Peter, ME; Tschopp, J; Yuan, J; Piacentini, M; Zhivotovsky, B; Melino, G

    2009-01-01

    Different types of cell death are often defined by morphological criteria, without a clear reference to precise biochemical mechanisms. The Nomenclature Committee on Cell Death (NCCD) proposes unified criteria for the definition of cell death and of its different morphologies, while formulating several caveats against the misuse of words and concepts that slow down progress in the area of cell death research. Authors, reviewers and editors of scientific periodicals are invited to abandon expressions like ‘percentage apoptosis’ and to replace them with more accurate descriptions of the biochemical and cellular parameters that are actually measured. Moreover, at the present stage, it should be accepted that caspase-independent mechanisms can cooperate with (or substitute for) caspases in the execution of lethal signaling pathways and that ‘autophagic cell death’ is a type of cell death occurring together with (but not necessarily by) autophagic vacuolization. This study details the 2009 recommendations of the NCCD on the use of cell death-related terminology including ‘entosis’, ‘mitotic catastrophe’, ‘necrosis’, ‘necroptosis’ and ‘pyroptosis’. PMID:18846107

  4. TNF-α inhibits aquaporin 5 expression in human salivary gland acinar cells via suppression of histone H4 acetylation.

    PubMed

    Yamamura, Yoshiko; Motegi, Katsumi; Kani, Kouichi; Takano, Hideyuki; Momota, Yukihiro; Aota, Keiko; Yamanoi, Tomoko; Azuma, Masayuki

    2012-08-01

    Sjögren's syndrome is a systemic autoimmune disease characterized by reductions in salivary and lacrimal secretions. The mechanisms underlying these reductions remain unclear. We have previously shown that TNF-α plays an important role in the destruction of acinar structures. Here we examined TNF-α's function in the expression of aquaporin (AQP) 5 in human salivary gland acinar cells. Immortalized human salivary gland acinar (NS-SV-AC) cells were treated with TNF-α, and then the expression levels of AQP5 mRNA and protein were analysed. In addition, the mechanisms underlying the reduction of AQP5 expression by TNF-α treatment were investigated. TNF-α-treatment of NS-SV-AC cells significantly suppressed the expression levels of AQP5 mRNA and protein, and reduced the net fluid secretion rate. We examined the expression and activation levels of DNA methyltransferases (Dnmts) in NS-SV-AC cells treated with TNF-α. However, no significant changes were observed in the expression or activation levels of Dnmt1, Dnmt3a or Dnmt3b. Although we also investigated the role of NF-κB activity in the TNF-α-induced suppression of AQP5 expression in NS-SV-AC cells, we detected similar TNF-α suppression of AQP5 expression in non-transfected cells and in a super-repressor form of IκBα cDNA-transfected cell clones. However, interestingly, chromatin immunoprecipitation analysis demonstrated a remarkable decrease in levels of acetylated histone H4 associated with the AQP5 gene promoter after treatment with TNF-α in NS-SV-AC cells. Therefore, our results may indicate that TNF-α inhibition of AQP5 expression in human salivary gland acinar cells is due to the epigenetic mechanism by suppression of acetylation of histone H4.

  5. Uptake and metabolism of D-glucose in isolated acinar and ductal cells from rat submandibular glands.

    PubMed

    Cetik, Sibel; Rzajeva, Aigun; Hupkens, Emeline; Malaisse, Willy J; Sener, Abdullah

    2014-07-01

    The present study deals with the possible effects of selected environmental agents upon the uptake and metabolism of d-glucose in isolated acinar and ductal cells from the rat submandibular salivary gland. In acinar cells, the uptake of d-[U-(14) C]glucose and its non-metabolised analogue 3-O-[(14) C-methyl]-d-glucose was not affected significantly by phloridzin (0.1 mM) or substitution of extracellular NaCl (115 mM) by an equimolar amount of CsCl, whilst cytochalasin B (20 μM) decreased significantly such an uptake. In ductal cells, both phloridzin and cytochalasin B decreased the uptake of d-glucose and 3-O-methyl-d-glucose. Although the intracellular space was comparable in acinar and ductal cells, the catabolism of d-glucose (2.8 or 8.3 mM) was two to four times higher in ductal cells than in acinar cells. Phloridzin (0.1 mM), ouabain (1.0 mM) and cytochalasin B (20 μM) all impaired d-glucose catabolism in ductal cells. Such was also the case in ductal cells incubated in the absence of extracellular Ca(2+) or in media in which NaCl was substituted by CsCl. It is proposed that the ductal cells in the rat submandibular gland are equipped with several systems mediating the insulin-sensitive, cytochalasin B-sensitive and phloridzin-sensitive transport of d-glucose across the plasma membrane.

  6. Increase in muscarinic stimulation-induced Ca(2+) response by adenovirus-mediated Stim1-mKO1 gene transfer to rat submandibular acinar cells in vivo.

    PubMed

    Morita, Takao; Nezu, Akihiro; Tojyo, Yosuke; Tanimura, Akihiko

    2013-10-01

    Adenoviruses have been used for gene transfer to salivary gland cells in vivo. Their use to study the function of salivary acinar cells was limited by a severe inflammatory response and by the destruction of fluid-secreting acinar cells. In the present study, low doses of adenovirus were administered to express Stim1-mKO1 by retrograde ductal injection to submandibular glands. The approach succeeded in increasing muscarinic stimulation-induced Ca(2+) responses in acinar cells without inflammation or decreased salivary secretions. This increased Ca(2+) response was notable upon weak muscarinic stimulation and was attributed to increased Ca(2+) release from internal stores and increased Ca(2+) entry. The basal Ca(2+) level was higher in Stim1-mKO1-expressing cells than in mKO1-expressing and non-expressing cells. Exposure of permeabilized submandibular acinar cells, where Ca(2+) concentration was fixed at 50 nM, to inositol 1,4,5-trisphosphate (IP3) produced similar effects on the release of Ca(2+) from stores in Stim1-mKO1-expressing and non-expressing cells. The low toxicity and relative specificity to acinar cells of the mild gene transfer method described herein are particularly useful for studying the molecular functions of salivary acinar cells in vivo, and may be applied to increase salivary secretions in experimental animals and human in future.

  7. A model system for the study of stimulus - enzyme secretion coupling in rat pancreatic acinar cells.

    PubMed

    Guderley, H; Heisler, S

    1980-08-01

    A superfusion technique was developed as a model system for the study of stimulus-secretion coupling in collagenase-dispersed rat pancreatic acinar cells. Cells (10(7)) were combined with a slurry of Biogel P-4 beads and the mixture was decanted into a plastic column (1.5 cm X 8.5 cm) and perfused with Krebs-Ringer. Amylase activity was determined in sequentially collected effusate fractions and used to estimate the secretory rate. Carbachol, carbachol plus dibutyryl cyclic AMP, cholecystokinin-pancreozymin, and the ionophore A-23187 all stimulated a rapid increase in the rate of secretion. Cell integrity was unaffected by these stimulants as evidenced microscopically and by the lack of lactate dehydrogenase activity in the effusates. Enzymes secreted in response to secretagogues were collected, concentrated, and isoelectrofocused on polyacrylamide gels. A film detection technique was developed to localize amylase activity. The model system has the following advantages: (1) secreted proteolytic products are removed from the vicinity of cells, thereby preventing direct cellular damage and hydrolysis of peptide agonist; (2) the need to add trypsin inhibitors is eliminated and only a minimal addition of albumin (0.001%) is required, thus allowing the separation and distortion-free analysis of secreted proteins; (3) the perfusion conditions can be changed rapidly without disturbing the cells. The model described is therefore well suited to the study of both molecular and kinetic events involved in the enzyme secretory phenomenon in exocrine pancreas. PMID:6164455

  8. [Thapsigargin-sensitive and insensitive intracellular calcium stores in acinar cells of the submandibular salivary gland in rats].

    PubMed

    Kopach, O V; Kruhlykov, I A; Voĭtenko, N V; Fedirko, N V

    2005-01-01

    Acinar cells of rat submandibular salivary gland are characterized by heterogeneity of intracellular Ca2+ stores. In the present work we have studied this heterogeneity using Arsenazo III dye to measure a cellular total calcium content and Fura-2/AM, to determine free cytosolic calcium concentration ([Ca2+]i). We have found that the amount of Ca2+ released by inhibition of Ca2+ ATPase of the ER with thapsigargin comprises approximately 30% of total ER calcium. This result was obtained in experiments on both intact and permeabilized acinar cells. We have also shown that both Ca2+ ATPase inhibition with thapsigargin and emptying the stores with acetylcholine (ACh) led to activation of store-operated Ca2+ influx (an increase in total calcium content of approximately 14%). In permeabilized cells application of ACh after preincubation with thapsigargin led to a further decrease in total cellular calcium content (approximately 38%). At the same time in intact cells it resulted in generation of [Ca2+]i transients with gradually decreasing amplitudes. Thus, ACh is capable of producing an additional release of Ca2+ from thapsigargin-insensitive stores. This additional release is IP3-dependent since it was completely blocked by heparin. We conclude that in acinar cells of rat submandibular gland thapsigargin-sensitive and thapsigargin-insensitive Ca2+ stores could exist.

  9. Quantitative description of the spatial arrangement of organelles in a polarised secretory epithelial cell: the salivary gland acinar cell

    PubMed Central

    MAYHEW, TERRY M.

    1999-01-01

    Previous quantitative descriptions of cellular ultrastructure have focused on spatial content (volume, surface area and number of organelles and membrane domains). It is possible to complement such descriptions by also quantifying spatial arrangements. Hitherto, applications of stereological methods for achieving this (notably, estimation of covariance and pair correlation functions) have been confined to organ and tissue levels. This study explores 3-dimensional subcellular arrangements of key organelles within acinar cells of rabbit parotid salivary glands, highly polarised epithelial cells specialised for exocrine secretion of α-amylase. It focuses on spatial arrangements of secretion product stores (zymogen granules), rough endoplasmic reticulum (RER) and mitochondria. Systematic random samples of electron microscopical fields of view from 3 rabbits were analysed using test grids bearing linear dipole probes of different sizes. Unbiased estimates of organelle volume densities were obtained by point counting and estimates of covariance and pair correlation functions by dipole counting. Plots of pair correlation functions against dipole length identified spatial arrangement differences between organelle types. Volumes within RER and mitochondrial compartments were positively correlated with themselves at distances below 4 μm and 2 μm respectively but were essentially randomly arranged at longer distances. In sharp contrast, zymogen granules were not randomly arranged. They were clustered at distances below 6–7 μm and more widely scattered at greater distances. These findings provide quantitative confirmation of the polarised arrangement of zymogen granules within acinar cells and further support for the relative invariance of biological organisation between subjects. PMID:10337960

  10. Whole exome sequencing reveals recurrent mutations in BRCA2 and FAT genes in acinar cell carcinomas of the pancreas

    PubMed Central

    Furukawa, Toru; Sakamoto, Hitomi; Takeuchi, Shoko; Ameri, Mitra; Kuboki, Yuko; Yamamoto, Toshiyuki; Hatori, Takashi; Yamamoto, Masakazu; Sugiyama, Masanori; Ohike, Nobuyuki; Yamaguchi, Hiroshi; Shimizu, Michio; Shibata, Noriyuki; Shimizu, Kyoko; Shiratori, Keiko

    2015-01-01

    Acinar cell carcinoma of the pancreas is a rare tumor with a poor prognosis. Compared to pancreatic ductal adenocarcinoma, its molecular features are poorly known. We studied a total of 11 acinar cell carcinomas, including 3 by exome and 4 by target sequencing. Exome sequencing revealed 65 nonsynonymous mutations and 22 indels with a mutation rate of 3.4 mutations/Mb per tumor, on average. By accounting for not only somatic but also germline mutations with loss of the wild-type allele, we identified recurrent mutations of BRCA2 and FAT genes. BRCA2 showed somatic or germline premature termination mutations, with loss of the wild-type allele in 3 of 7 tumors. FAT1, FAT3, and FAT4 showed somatic or germline missense mutations in 4 of 7 tumors. The germline FAT mutations were with loss of the wild-type allele. Loss of BRCA2 expression was observed in 5 of 11 tumors. One patient with a BRCA2-mutated tumor experienced complete remission of liver metastasis following cisplatinum chemotherapy. In conclusion, acinar cell carcinomas show a distinct mutation pattern and often harbor somatic or germline mutations of BRCA2 and FAT genes. This result may warrant assessment of BRCA2 abrogation in patients with the carcinoma to determine their sensitivity to chemotherapy. PMID:25743105

  11. Phorbol esters and A23187 regulate Na/sup +/=K/sup +/-pump activity in pancreatic acinar cells

    SciTech Connect

    Hootman, S.R.; Brown, M.E.; Williams, J.A.

    1987-04-01

    To clarify the subcellular mechanisms that mediate stimulation of Na/sup +/-K/sup +/-pump activity in pancreatic acinar cells by cholinergic agonists, the authors examined the effects of the phorbol ester, 12-O-tetradecanoylphorbol-13-acetate (TPA) and the Ca/sup 2 +/ ionophore A23187 on (/sup 3/H)ouabain binding to dispersed guinea pig pancreatic acinar cells under conditions in which binding reflects the average rate of pump cycling. The phorbol ester more than doubled Na/sup +/-K/sup +/-pump activity as did the diacylglycerol analogue, 1-oleoyl-2-acetolyl-sn-3-glycerol. A23187 increased pump activity by a maximum of 31% at 0.3 ..mu..M but was progressively inhibitory at higher concentrations. The stimulatory effects of TPA and A23187 were additive, although either secretagogue elicited a less than additive response when added together with a maximally effective concentration of the cholinergic agonist, carbachol. Removal of extracellular Ca/sup 2 +/ had little effect on the pump response to TPA and did not reduce the maximal effect of A23187 but abolished the inhibitory effect seen at high ionophore concentrations in Ca/sup 2 +/-containing medium. These results indicate that both Ca/sup 2 +/ and protein kinase c are involved in regulating Na/sup +/-K/sup +/-pump activity in the pancreatic acinar cell.

  12. Long-term dexamethasone treatment alters the histomorphology of acinar cells in rat parotid and submandibular glands.

    PubMed

    Bighetti, Bruna B; d Assis, Gerson F; Vieira, Danilo C; Violato, Natalia M; Cestari, Tania M; Taga, Rumio; Bosqueiro, José R; Rafacho, Alex

    2014-10-01

    Glucocorticoids (GCs) induce insulin resistance (IR), a condition known to alter oral homeostasis. This study investigated the effects of long-term dexamethasone administration on morphofunctional aspects of salivary glands. Male Wistar rats received daily injections of dexamethasone [0.1 mg/kg body weight (b.w.), intraperitoneally] for 10 days (DEX), whereas control rats received saline. Subsequently, glycaemia, insulinaemia, insulin secretion and salivary flow were analysed. The parotid and submandibular glands were collected for histomorphometric evaluation and Western blot experiments. The DEX rats were found to be normoglycaemic, hyperinsulinaemic, insulin resistant and glucose intolerant (P < 0.05). DEX rat islets secreted more insulin in response to glucose (P < 0.05). DEX rats had significant reductions in the masses of the parotid (29%) and submandibular (16%) glands (P < 0.05) that was associated with reduced salivary flux rate. The hypotrophy in both glands observed in the DEX group was associated with marked reduction in the volume of the acinar cells in these glands of 50% and 26% respectively (P < 0.05). The total number of acinar cells was increased in the submandibular glands of the DEX rats (P < 0.05) but not in the parotid glands. The levels of proteins related to insulin and survival signalling in both glands did not differ between the groups. In conclusion, the long-term administration of dexamethasone caused IR, which was associated with significant reductions in both mass and flux rate of the salivary glands. The parotid and submandibular glands exhibited reduced acinar cell volume; however, the submandibular glands displayed acinar hyperplasia, indicating a gland-specific response to GCs. Our data emphasize that GC-based therapies and insulin-resistant states have a negative impact on salivary gland homeostasis.

  13. Long-term dexamethasone treatment alters the histomorphology of acinar cells in rat parotid and submandibular glands

    PubMed Central

    Bighetti, Bruna B; Assis, Gerson F d; Vieira, Danilo C; Violato, Natalia M; Cestari, Tania M; Taga, Rumio; Bosqueiro, José R; Rafacho, Alex

    2014-01-01

    Glucocorticoids (GCs) induce insulin resistance (IR), a condition known to alter oral homeostasis. This study investigated the effects of long-term dexamethasone administration on morphofunctional aspects of salivary glands. Male Wistar rats received daily injections of dexamethasone [0.1 mg/kg body weight (b.w.), intraperitoneally] for 10 days (DEX), whereas control rats received saline. Subsequently, glycaemia, insulinaemia, insulin secretion and salivary flow were analysed. The parotid and submandibular glands were collected for histomorphometric evaluation and Western blot experiments. The DEX rats were found to be normoglycaemic, hyperinsulinaemic, insulin resistant and glucose intolerant (P < 0.05). DEX rat islets secreted more insulin in response to glucose (P < 0.05). DEX rats had significant reductions in the masses of the parotid (29%) and submandibular (16%) glands (P < 0.05) that was associated with reduced salivary flux rate. The hypotrophy in both glands observed in the DEX group was associated with marked reduction in the volume of the acinar cells in these glands of 50% and 26% respectively (P < 0.05). The total number of acinar cells was increased in the submandibular glands of the DEX rats (P < 0.05) but not in the parotid glands. The levels of proteins related to insulin and survival signalling in both glands did not differ between the groups. In conclusion, the long-term administration of dexamethasone caused IR, which was associated with significant reductions in both mass and flux rate of the salivary glands. The parotid and submandibular glands exhibited reduced acinar cell volume; however, the submandibular glands displayed acinar hyperplasia, indicating a gland-specific response to GCs. Our data emphasize that GC-based therapies and insulin-resistant states have a negative impact on salivary gland homeostasis. PMID:25186305

  14. Knockdown of GRP78 promotes apoptosis in pancreatic acinar cells and attenuates the severity of cerulein and LPS induced pancreatic inflammation.

    PubMed

    Liu, Yong; Yang, Lie; Chen, Ke-Ling; Zhou, Bin; Yan, Hui; Zhou, Zong-Guang; Li, Yuan

    2014-01-01

    Acute pancreatitis (AP) is a potentially lethal disease characterized by inflammation and parenchymal cell death; also, the severity of AP correlates directly with necrosis and inversely with apoptosis. However, mechanisms of regulating cell death in AP remain unclear. The endoplasmic reticulum (ER) chaperone protein GRP78 has anti-apoptotic properties, in addition to modulating ER stress responses. This study used RNA interference (RNAi) approach to investigate the potential role of GRP78 in regulating apoptosis during AP. In vitro models of AP were successfully developed by treating AR42J cells with cerulein or cerulein plus lipoplysaccharide (LPS). There was more pancreatic inflammation and less apoptosis with the cerulein plus LPS treatment. Furthermore, knockdown of GRP78 expression markedly promoted apoptosis and reduced necrosis in pancreatic acinar cells. This was accomplished by enhancing the activation of caspases and inhibiting the activity of X-linked inhibitor of apoptosis protein (XIAP), as well as a receptor interacting protein kinase-1(RIPK1), which is a key mediator of necrosis. This attenuated the severity of pancreatic inflammation, especially after cerulein plus LPS treatment. In conclusion, these findings indicate that GRP78 plays an anti-apoptotic role in regulating the cell death response during AP. Therefore, GRP78 is a potential therapeutic target for AP. PMID:24643222

  15. Stromal ETS2 Regulates Chemokine Production and Immune Cell Recruitment during Acinar-to-Ductal Metaplasia.

    PubMed

    Pitarresi, Jason R; Liu, Xin; Sharma, Sudarshana M; Cuitiño, Maria C; Kladney, Raleigh D; Mace, Thomas A; Donohue, Sydney; Nayak, Sunayana G; Qu, Chunjing; Lee, James; Woelke, Sarah A; Trela, Stefan; LaPak, Kyle; Yu, Lianbo; McElroy, Joseph; Rosol, Thomas J; Shakya, Reena; Ludwig, Thomas; Lesinski, Gregory B; Fernandez, Soledad A; Konieczny, Stephen F; Leone, Gustavo; Wu, Jinghai; Ostrowski, Michael C

    2016-09-01

    Preclinical studies have suggested that the pancreatic tumor microenvironment both inhibits and promotes tumor development and growth. Here we establish the role of stromal fibroblasts during acinar-to-ductal metaplasia (ADM), an initiating event in pancreatic cancer formation. The transcription factor V-Ets avian erythroblastosis virus E26 oncogene homolog 2 (ETS2) was elevated in smooth muscle actin-positive fibroblasts in the stroma of pancreatic ductal adenocarcinoma (PDAC) patient tissue samples relative to normal pancreatic controls. LSL-Kras(G12D/+); LSL-Trp53(R172H/+); Pdx-1-Cre (KPC) mice showed that ETS2 expression initially increased in fibroblasts during ADM and remained elevated through progression to PDAC. Conditional ablation of Ets-2 in pancreatic fibroblasts in a Kras(G12D)-driven mouse ADM model decreased the amount of ADM events. ADMs from fibroblast Ets-2-deleted animals had reduced epithelial cell proliferation and increased apoptosis. Surprisingly, fibroblast Ets-2 deletion significantly altered immune cell infiltration into the stroma, with an increased CD8+ T-cell population, and decreased presence of regulatory T cells (Tregs), myeloid-derived suppressor cells, and mature macrophages. The mechanism involved ETS2-dependent chemokine ligand production in fibroblasts. ETS2 directly bound to regulatory sequences for Ccl3, Ccl4, Cxcl4, Cxcl5, and Cxcl10, a group of chemokines that act as potent mediators of immune cell recruitment. These results suggest an unappreciated role for ETS2 in fibroblasts in establishing an immune-suppressive microenvironment in response to oncogenic Kras(G12D) signaling during the initial stages of tumor development. PMID:27659014

  16. Bone morphogenetic protein-6 is a marker of serous acinar cell differentiation in normal and neoplastic human salivary gland.

    PubMed

    Heikinheimo, K A; Laine, M A; Ritvos, O V; Voutilainen, R J; Hogan, B L; Leivo, I V; Heikinheimo, A K

    1999-11-15

    Bone morphogenetic protein (BMP-6, also known as vegetal-pale-gene-related and decaplentaplegic-vegetal-related) is a member of the transforming growth factor-beta superfamily of multifunctional signaling molecules. BMP-6 appears to play various biological roles in developing tissues, including regulation of epithelial differentiation. To study the possible involvement of BMP-6 in normal and neoplastic human salivary glands, we compared its mRNA and protein expression in 4 fetal and 15 adult salivary glands and in 22 benign and 32 malignant salivary gland tumors. In situ hybridization and Northern blot analysis indicated that BMP-6 transcripts are expressed at low levels in acinar cells of adult submandibular glands but not in ductal or stromal cells. BMP-6 was immunolocated specifically in serous acini of parotid and submandibular glands. None was found in primitive fetal acini or any other types of cell in adult salivary glands, including mucous acini and epithelial cells of intercalated, striated, and excretory ducts. All 16 cases of acinic cell carcinoma consistently exhibited cytoplasmic BMP-6 staining in the acinar tumor cells. Other cell types in these tumors, including intercalated duct-like cells, clear, vacuolated cells, and nonspecific glandular cells, exhibited no cytoplasmic BMP-6 staining. Other benign and malignant salivary gland tumors lacked BMP-6 immunoreactivity, except in areas of squamous differentiation. The results indicate that in salivary glands, BMP-6 expression is uniquely associated with acinar cell differentiation and suggest that BMP-6 may play a role in salivary gland function. More importantly, our experience of differential diagnostic problems related to salivary gland tumors suggests that the demonstration of consistent and specific BMP-6 immunoreactivity in acinic cell carcinoma is likely to be of clinical value.

  17. Ca²⁺ signaling and regulation of fluid secretion in salivary gland acinar cells.

    PubMed

    Ambudkar, Indu S

    2014-06-01

    Neurotransmitter stimulation of plasma membrane receptors stimulates salivary gland fluid secretion via a complex process that is determined by coordinated temporal and spatial regulation of several Ca(2+) signaling processes as well as ion flux systems. Studies over the past four decades have demonstrated that Ca(2+) is a critical factor in the control of salivary gland function. Importantly, critical components of this process have now been identified, including plasma membrane receptors, calcium channels, and regulatory proteins. The key event in activation of fluid secretion is an increase in intracellular [Ca(2+)] ([Ca(2+)]i) triggered by IP3-induced release of Ca(2+) from ER via the IP3R. This increase regulates the ion fluxes required to drive vectorial fluid secretion. IP3Rs determine the site of initiation and the pattern of [Ca(2+)]i signal in the cell. However, Ca(2+) entry into the cell is required to sustain the elevation of [Ca(2+)]i and fluid secretion. This Ca(2+) influx pathway, store-operated calcium influx pathway (SOCE), has been studied in great detail and the regulatory mechanisms as well as key molecular components have now been identified. Orai1, TRPC1, and STIM1 are critical components of SOCE and among these, Ca(2+) entry via TRPC1 is a major determinant of fluid secretion. The receptor-evoked Ca(2+) signal in salivary gland acinar cells is unique in that it starts at the apical pole and then rapidly increases across the cell. The basis for the polarized Ca(2+) signal can be ascribed to the polarized arrangement of the Ca(2+) channels, transporters, and signaling proteins. Distinct localization of these proteins in the cell suggests compartmentalization of Ca(2+) signals during regulation of fluid secretion. This chapter will discuss new concepts and findings regarding the polarization and control of Ca(2+) signals in the regulation of fluid secretion.

  18. Apical Ca2+-activated potassium channels in mouse parotid acinar cells.

    PubMed

    Almassy, Janos; Won, Jong Hak; Begenisich, Ted B; Yule, David I

    2012-02-01

    Ca(2+) activation of Cl and K channels is a key event underlying stimulated fluid secretion from parotid salivary glands. Cl channels are exclusively present on the apical plasma membrane (PM), whereas the localization of K channels has not been established. Mathematical models have suggested that localization of some K channels to the apical PM is optimum for fluid secretion. A combination of whole cell electrophysiology and temporally resolved digital imaging with local manipulation of intracellular [Ca(2+)] was used to investigate if Ca(2+)-activated K channels are present in the apical PM of parotid acinar cells. Initial experiments established Ca(2+)-buffering conditions that produced brief, localized increases in [Ca(2+)] after focal laser photolysis of caged Ca(2+). Conditions were used to isolate K(+) and Cl(-) conductances. Photolysis at the apical PM resulted in a robust increase in K(+) and Cl(-) currents. A localized reduction in [Ca(2+)] at the apical PM after photolysis of Diazo-2, a caged Ca(2+) chelator, resulted in a decrease in both K(+) and Cl(-) currents. The K(+) currents evoked by apical photolysis were partially blocked by both paxilline and TRAM-34, specific blockers of large-conductance "maxi-K" (BK) and intermediate K (IK), respectively, and almost abolished by incubation with both antagonists. Apical TRAM-34-sensitive K(+) currents were also observed in BK-null parotid acini. In contrast, when the [Ca(2+)] was increased at the basal or lateral PM, no increase in either K(+) or Cl(-) currents was evoked. These data provide strong evidence that K and Cl channels are similarly distributed in the apical PM. Furthermore, both IK and BK channels are present in this domain, and the density of these channels appears higher in the apical versus basolateral PM. Collectively, this study provides support for a model in which fluid secretion is optimized after expression of K channels specifically in the apical PM.

  19. G protein in stimulation of PI hydrolysis by CCK (cholecystokinin) in isolated rat pancreatic acinar cells

    SciTech Connect

    Matozaki, Takashi; Sakamoto, Choitsu; Nagao, Munehiko; Nishizaki, Hogara; Baba, Shigeaki )

    1988-11-01

    To clarify the possible role of a guanine nucleotide-binding protein (G protein) in the signal transducing system activated by cholecystokinin (CCK), actions of CCK on rat pancreatic acini were compared with those of fluoride, a well-known activator of stimulatory (G{sub s}) or inhibitory (G{sub i}) G protein. When acini were incubated with increasing concentrations of either CCK-octapeptide (CCK8) or NaF, a maximal stimulation of amylase release from acini occurred at 100 pM CCK8 or 10 mM NaF, respectively; this secretory rate decreased as CCK8 or NaF concentration was increased. NaF caused an increase in cytoplasmic Ca{sup 2+} concentration from the internal Ca{sup 2+} store and stimulated accumulation of inositol phosphates in acini, as observed with CCK. Guanylimidodiphosphate activated the generation of inositol phosphates in the ({sup 3}H)inositol-labeled pancreatic acinar cell membrane preparation, with half-maximal and maximal stimulation at 1 and 10 {mu}M, respectively. Furthermore, the effects of submaximal CCK concentrations on inositol phosphate accumulation in membranes were markedly potentiated in the presence of 100 {mu}M GTP, which alone was ineffective. Combined findings of the present study strongly suggest that pancreatic CCK receptors are probably coupled to the activation of polyphosphoinositide (PI) breakdown by a G protein, which appears to be fluoride sensitive but is other than G{sub s}- or G{sub i}-like protein.

  20. Acinar cell carcinomas of the pancreas: a molecular analysis in a series of 57 cases.

    PubMed

    Bergmann, Frank; Aulmann, Sebastian; Sipos, Bence; Kloor, Matthias; von Heydebreck, Anja; Schweipert, Johannes; Harjung, Andreas; Mayer, Philipp; Hartwig, Werner; Moldenhauer, Gerhard; Capper, David; Dyckhoff, Gerhard; Freier, Kolja; Herpel, Esther; Schleider, Anja; Schirmacher, Peter; Mechtersheimer, Gunhild; Klöppel, Günter; Bläker, Hendrik

    2014-12-01

    Pancreatic acinar cell carcinomas (PACs) are rare but are distinct aggressive neoplasms that phenotypically differ from pancreatic ductal adenocarcinomas (PDACs) and pancreatic neuroendocrine neoplasms (PNENs). Despite recent work on the genetic changes of PACs, their molecular pathogenesis is still poorly understood. In this study, we focus on a comparative genomic hybridization analysis. Based on frequent chromosomal imbalances, the involvement of DCC and c-MYC in the pathogenesis of PACs is further investigated. Moreover, we examine markers harboring potential therapeutic relevance (K-RAS, BRAF, EGFR, MGMT, HSP90, L1CAM, Her2). PACs revealed a microsatellite stable, chromosomal unstable genotype, defined by recurrent chromosomal losses of 1p, 3p, 4q, 5q, 6q, 8p, 9p, 11q, 13q, 16q, and 18, as well as gains of 1q, 7, 8q, 12, 17q, and 20q. Subsets of PAC displayed reduction/loss of DCC (79 %) and c-MYC-amplification (17 %). Significant EGFR expression occurred in 42 %, HSP90 expression in 98 %, L1CAM expression in 72 %, and loss of MGMT in 26 %. Two cases carried a K-RAS mutation. Mutations of EGFR or BRAF were not detected. All cases were Her2/neu-negative. PACs display characteristic chromosomal imbalances which are distinctly different from those in pancreatic ductal adenocarcinomas and pancreatic neuroendocrine neoplasms. Our findings suggest that DCC and c-MYC alterations may play an important role in the pathogenesis of PACs. Furthermore, EGFR, MGMT, HSP90, and L1CAM may be useful as therapeutic markers and predictors of response to therapy in a subset of PACs. PMID:25298229

  1. Expression, localization, and functional role for synaptotagmins in pancreatic acinar cells

    PubMed Central

    Falkowski, Michelle A.; Thomas, Diana D. H.; Messenger, Scott W.; Martin, Thomas F.

    2011-01-01

    Secretagogue-induced changes in intracellular Ca2+ play a pivotal role in secretion in pancreatic acini yet the molecules that respond to Ca2+ are uncertain. Zymogen granule (ZG) exocytosis is regulated by soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) complexes. In nerve and endocrine cells, Ca2+-stimulated exocytosis is regulated by the SNARE-associated family of proteins termed synaptotagmins. This study examined a potential role for synaptotagmins in acinar secretion. RT-PCR revealed that synaptotagmin isoforms 1, 3, 6, and 7 are present in isolated acini. Immunoblotting and immunofluorescence using three different antibodies demonstrated synaptotagmin 1 immunoreactivity in apical cytoplasm and ZG fractions of acini, where it colocalized with vesicle-associated membrane protein 2. Synaptotagmin 3 immunoreactivity was detected in membrane fractions and colocalized with an endolysosomal marker. A potential functional role for synaptotagmin 1 in secretion was indicated by results that introduction of synaptotagmin 1 C2AB domain into permeabilized acini inhibited Ca2+-dependent exocytosis by 35%. In contrast, constructs of synaptotagmin 3 had no effect. Confirmation of these findings was achieved by incubating intact acini with an antibody specific to the intraluminal domain of synaptotagmin 1, which is externalized following exocytosis. Externalized synaptotagmin 1 was detected exclusively along the apical membrane. Treatment with CCK-8 (100 pM, 5 min) enhanced immunoreactivity by fourfold, demonstrating that synaptotagmin is inserted into the apical membrane during ZG fusion. Collectively, these data indicate that acini express synaptotagmin 1 and support that it plays a functional role in secretion whereas synaptotagmin 3 has an alternative role in endolysosomal membrane trafficking. PMID:21636530

  2. The perinuclear space of pancreatic acinar cells and the synthetic pathway of zymogen in Scorpaena scrofa L.: ultrastructural aspects.

    PubMed

    Gilloteaux, Jacques; Kashouty, Rabih; Yono, Noor

    2008-02-01

    Electron microscopic examination of exocrine pancreatic tissues from the fish Scorpaena scrofa L., probably captured while replenishing the acinar cells, shows two main functional cell morphologies of the same cell type. One cell functional aspect contains numerous well-contrasted small vesicles, the zymogenic vesicles. The other functional morphology is mainly represented by a few cells containing large apical zymogen vesicles with many empty RER cisterns. In our observations, the zymogenic vesicles are always studded with ribosomes. The main cytological finding is to report that zymogenic vesicles can be extruded from the perinuclear space and it confirms the suspected, synthetic activity of this cell compartment. The pool of zymogenic vesicles, maintaining their coat of ribosomes, then fuses and transfers their content into the cis Golgi complex network. Finally, the zymogen vesicles are produced following the classical secretory pathway from the trans Golgi saccular network into the supranuclear, apical region of the acinar cells where the largest vesicles concentrate their content until secretion. PMID:17961618

  3. Differences in claudin synthesis in primary cultures of acinar cells from rat salivary gland are correlated with the specific three-dimensional organization of the cells.

    PubMed

    Qi, Bing; Fujita-Yoshigaki, Junko; Michikawa, Hiromi; Satoh, Keitaro; Katsumata, Osamu; Sugiya, Hiroshi

    2007-07-01

    Tight junctions are essential for the maintenance of epithelial cell polarity. We have previously established a system for the primary culture of salivary parotid acinar cells that retain their ability to generate new secretory granules and to secrete proteins in a signal-dependent manner. Because cell polarity and cell-cell adhesion are prerequisites for the formation of epithelial tissues, we have investigated the structure of the tight junctions in these cultures. We have found two types of cellular organization in the culture: monolayers and semi-spherical clusters. Electron microscopy has revealed tight junctions near the apical region of the lateral membranes between cells in the monolayers and cells at the surface of the clusters. The cells in the interior of the clusters also have tight junctions and are organized around a central lumen. These interior cells retain more secretory granules than the surface or monolayer cells, suggesting that they maintain their original character as acinar cells. The synthesis of claudin-4 increases during culture, although it is not detectable in the cells immediately after isolation from the glands. Immunofluorescence microscopy has shown that claudin-4 is synthesized in the monolayers and at the surface of the clusters, but not inside the clusters. Only claudin-3, which is present in the original acinar cells following isolation and in the intact gland, has been detected inside the clusters. These results suggest that differences in claudin expression are related to the three-dimensional structures of the cell cultures and reflect their ability to function as acinar cells.

  4. Human salivary gland acinar cells spontaneously form three-dimensional structures and change the protein expression patterns.

    PubMed

    Chan, Yen-Hui; Huang, Tsung-Wei; Young, Tai-Horng; Lou, Pei-Jen

    2011-11-01

    Applying tissue engineering principles to design an auto-secretory device is a potential solution for patients suffering loss of salivary gland function. However, the largest challenge in implementing this solution is the primary culture of human salivary gland cells, because the cells are highly differentiated and difficult to expand in vitro. This situation leads to the lack of reports on the in vitro cell biology and physiology of human salivary gland cells. This study used a low-calcium culture system to selectively cultivate human parotid gland acinar (PGAC) cells from tissues with high purity in cell composition. This condition enables PGAC cells to continuously proliferate and retain the phenotypes of epithelial acinar cells to express secreting products (α-amylase) and function-related proteins (aquaporin-3, aquaporin-5, and ZO-1). Notably, when the cells reached confluence, three-dimensional (3D) cell aggregates were observed in crowded regions. These self-formed cell spheres were termed post-confluence structures (PCSs). Unexpectedly, despite being cultured in the same media, cells in PCSs exhibited higher expression levels and different expression patterns of function-related proteins compared to the two-dimensional (2D) cells. Translocation of aquoporin-3 from cytosolic to alongside the cell boundaries, and of ZO-1 molecules to the boundary of the PCSs were also observed. These observations suggest that when PGAC cells cultured on the 2D substrate would form PCSs without the help of 3D scaffolds and retain certain differentiation and polarity. This phenomenon implies that it is possible to introduce 2D substrates instead of 3D scaffolds into artificial salivary gland tissue engineering.

  5. Insulation of a G protein-coupled receptor on the plasmalemmal surface of the pancreatic acinar cell

    PubMed Central

    1995-01-01

    Receptor desensitization is a key process for the protection of the cell from continuous or repeated exposure to high concentrations of an agonist. Well-established mechanisms for desensitization of guanine nucleotide-binding protein (G protein)-coupled receptors include phosphorylation, sequestration/internalization, and down-regulation. In this work, we have examined some mechanisms for desensitization of the cholecystokinin (CCK) receptor which is native to the pancreatic acinar cell, and have found the predominant mechanism to be distinct from these recognized processes. Upon fluorescent agonist occupancy of the native receptor, it becomes "insulated" from the effects of acid washing and becomes immobilized on the surface of the plasma membrane in a time- and temperature-dependent manner. This localization was assessed by ultrastructural studies using a colloidal gold conjugate of CCK, and lateral mobility of the receptor was assessed using fluorescence recovery after photobleaching. Of note, recent application of the same morphologic techniques to a CCK receptor-bearing Chinese hamster ovary cell line demonstrated prominent internalization via the clathrin-dependent endocytic pathway, as well as entry into caveolae (Roettger, B.F., R.U. Rentsch, D. Pinon, E. Holicky, E. Hadac, J.M. Larkin, and L.J. Miller, 1995, J. Cell Biol. 128: 1029-1041). These organelles are not observed to represent prominent compartments for the same receptor to traverse in the acinar cell, although fluorescent insulin is clearly internalized in these cells via receptor-mediated endocytosis. In this work, the rate of lateral mobility of the CCK receptor is observed to be similar in both cell types (1-3 x 10(-10) cm2/s), while the fate of the agonist-occupied receptor is quite distinct in each cell. This supports the unique nature of desensitization processes which occur in a cell-specific manner. A plasmalemmal site of insulation of this important receptor on the pancreatic acinar cell

  6. Postnatal Pancreas of Mice Contains Tripotent Progenitors Capable of Giving Rise to Duct, Acinar, and Endocrine Cells In Vitro

    PubMed Central

    Ghazalli, Nadiah; Mahdavi, Alborz; Feng, Tao; Jin, Liang; Kozlowski, Mark T.; Hsu, Jasper; Riggs, Arthur D.; Tirrell, David A.

    2015-01-01

    Postnatal pancreas is a potential source for progenitor cells to generate endocrine β-cells for treating type 1 diabetes. However, it remains unclear whether young (1-week-old) pancreas harbors multipotent progenitors capable of differentiating into duct, acinar, and endocrine cells. Laminin is an extracellular matrix (ECM) protein important for β-cells' survival and function. We established an artificial extracellular matrix (aECM) protein that contains the functional IKVAV (Ile-Lys-Val-Ala-Val) sequence derived from laminin (designated aECM-lam). Whether IKVAV is necessary for endocrine differentiation in vitro is unknown. To answer these questions, we cultured single cells from 1-week-old pancreas in semi-solid media supplemented with aECM-lam, aECM-scr (which contains a scrambled sequence instead of IKVAV), or Matrigel. We found that colonies were generated in all materials. Individual colonies were examined by microfluidic reverse transcription-polymerase chain reaction, immunostaining, and electron microscopy analyses. The majority of the colonies expressed markers for endocrine, acinar, and ductal lineages, demonstrating tri-lineage potential of individual colony-forming progenitors. Colonies grown in aECM-lam expressed higher levels of endocrine markers Insulin1, Insulin2, and Glucagon compared with those grown in aECM-scr and Matrigel, indicating that the IKVAV sequence enhances endocrine differentiation. In contrast, Matrigel was inhibitory for endocrine gene expression. Colonies grown in aECM-lam displayed the hallmarks of functional β-cells: mature insulin granules and glucose-stimulated insulin secretion. Colony-forming progenitors were enriched in the CD133high fraction and among 230 micro-manipulated single CD133high cells, four gave rise to colonies that expressed tri-lineage markers. We conclude that young postnatal pancreas contains multipotent progenitor cells and that aECM-lam promotes differentiation of β-like cells in vitro. PMID:25941840

  7. Postnatal Pancreas of Mice Contains Tripotent Progenitors Capable of Giving Rise to Duct, Acinar, and Endocrine Cells In Vitro.

    PubMed

    Ghazalli, Nadiah; Mahdavi, Alborz; Feng, Tao; Jin, Liang; Kozlowski, Mark T; Hsu, Jasper; Riggs, Arthur D; Tirrell, David A; Ku, H Teresa

    2015-09-01

    Postnatal pancreas is a potential source for progenitor cells to generate endocrine β-cells for treating type 1 diabetes. However, it remains unclear whether young (1-week-old) pancreas harbors multipotent progenitors capable of differentiating into duct, acinar, and endocrine cells. Laminin is an extracellular matrix (ECM) protein important for β-cells' survival and function. We established an artificial extracellular matrix (aECM) protein that contains the functional IKVAV (Ile-Lys-Val-Ala-Val) sequence derived from laminin (designated aECM-lam). Whether IKVAV is necessary for endocrine differentiation in vitro is unknown. To answer these questions, we cultured single cells from 1-week-old pancreas in semi-solid media supplemented with aECM-lam, aECM-scr (which contains a scrambled sequence instead of IKVAV), or Matrigel. We found that colonies were generated in all materials. Individual colonies were examined by microfluidic reverse transcription-polymerase chain reaction, immunostaining, and electron microscopy analyses. The majority of the colonies expressed markers for endocrine, acinar, and ductal lineages, demonstrating tri-lineage potential of individual colony-forming progenitors. Colonies grown in aECM-lam expressed higher levels of endocrine markers Insulin1, Insulin2, and Glucagon compared with those grown in aECM-scr and Matrigel, indicating that the IKVAV sequence enhances endocrine differentiation. In contrast, Matrigel was inhibitory for endocrine gene expression. Colonies grown in aECM-lam displayed the hallmarks of functional β-cells: mature insulin granules and glucose-stimulated insulin secretion. Colony-forming progenitors were enriched in the CD133(high) fraction and among 230 micro-manipulated single CD133(high) cells, four gave rise to colonies that expressed tri-lineage markers. We conclude that young postnatal pancreas contains multipotent progenitor cells and that aECM-lam promotes differentiation of β-like cells in vitro.

  8. Programmed cell death in neurodevelopment.

    PubMed

    Yamaguchi, Yoshifumi; Miura, Masayuki

    2015-02-23

    Programmed cell death (PCD) is an evolutionarily conserved contributor to nervous system development. In the vertebrate peripheral nervous system, PCD is the basis of the neurotrophic theory, whereby cell death results from a surplus of neurons relative to target and competition for neurotrophic factors. In addition to stochastic cell death, PCD can be intrinsically determined by cell lineage or position and timing in both invertebrate and vertebrate central nervous systems. The underlying PCD molecular mechanisms include intrinsic transcription factor cascades and regulators of competence/susceptibility to cell death. Here, we provide a framework for understanding neural PCD from its regulation to its functions.

  9. CCN6 knockdown disrupts acinar organization of breast cells in three-dimensional cultures through up-regulation of type III TGF-β receptor.

    PubMed

    Pal, Anupama; Huang, Wei; Toy, Kathy A; Kleer, Celina G

    2012-11-01

    While normal cells in the human breast are organized into acinar structures, disruption of the acinar architecture is a hallmark of cancer. In a three-dimensional model of morphogenesis, we show that down-regulation of the matrix-associated tumor suppressor protein CCN6 (WNT1-inducible-signaling pathway protein 3) disrupts breast epithelial cell polarity and organization into acini through up-regulation of the type III transforming growth factor-β receptor (TβRIII or betaglycan). Down-regulation of CCN6 in benign breast cells led to loss of tissue polarity and resulted in cellular disorganization with loss of α6 integrin-rich basement membrane and the basolateral polarity protein E-cadherin. Silencing of TβRIII with shRNA and siRNA rescued the ability of breast epithelial cells to form polarized acinar structures with reduced matrix invasion and restored the correct expression of α6 integrin and E-cadherin. Conversely, CCN6 overexpression in aggressive breast cancer cells reduced TβRIII in vitro and in a xenograft model of CCN6 overexpression. The relevance of our studies to human breast cancer is highlighted by the finding that CCN6 protein levels are inversely associated with TβRIII protein in 64%of invasive breast carcinomas. These results reveal a novel function of the matricellular protein CCN6 and establish a mechanistic link between CCN6 and TβRIII in maintaining acinar organization in the breast.

  10. Distinct contributions by ionotropic purinoceptor subtypes to ATP-evoked calcium signals in mouse parotid acinar cells

    PubMed Central

    Bhattacharya, Sumit; Verrill, Douglas S; Carbone, Kristopher M; Brown, Stefanie; Yule, David I; Giovannucci, David R

    2012-01-01

    There is emerging consensus that P2X4 and P2X7 ionotropic purinoceptors (P2X4R and P2X7R) are critical players in regulating [Ca2+]i dynamics and fluid secretion in the salivary gland. In contrast, details regarding their compartmentalization and selective activation, contributions to the spatiotemporal properties of intracellular signals and roles in regulating protein exocytosis and ion channel activity have remained largely undefined. To address these concerns, we profiled mouse parotid acinar cells using live-cell imaging to follow the spatial and temporal features of ATP-evoked Ca2+ dynamics and exocytotic activity. Selective activation of P2X7Rs revealed an apical-to-basal [Ca2+]i signal that initiated at the sub-luminal border and propagated with a wave speed estimated at 17.3 ± 4.3 μm s−1 (n = 6). The evoked Ca2+ spike consisted of Ca2+ influx and Ca2+-induced Ca2+ release from intracellular Ca2+ channels. In contrast, selective activation of P2X4Rs induced a Ca2+ signal that initiated basally and propagated toward the lumen with a wave speed of 4.3 ± 0.2 μm s−1 (n = 8) that was largely independent of intracellular Ca2+ channel blockade. Consistent with these observations, P2X7R expression was enriched in the sub-luminal regions of acinar cells while P2X4R appeared localized to basal areas. In addition, we showed that P2X4R and P2X7R activation evokes exocytosis in parotid acinar cells. Our studies also demonstrate that the P2X4R-mediated [Ca2+]i rise and subsequent protein exocytosis was enhanced by ivermectin (IVR). Thus, in addition to furthering our understanding of salivary gland physiology, this study identifies P2X4R as a potential target for treatment of salivary hypofunction diseases. PMID:22451435

  11. Morphometric studies of secretory granule formation in mouse pancreatic acinar cells. Dissecting the early structural changes following pilocarpine injection

    PubMed Central

    HAMMEL, ILAN; SHOR-HAZAN, OSNAT; ELDAR, TORA; AMIHAI, DINA; LEW, SYLVIA

    1999-01-01

    Secretory granule formation in pancreatic acinar cells is known to involve massive membrane flow. In previous studies we have undertaken morphometry of the regranulation mechanism in these cells and in mast cells as a model for cellular membrane movement. In our current work, electron micrographs of pancreatic acinar cells from ICR mice were taken at several time points after extensive degranulation induced by pilocarpine injection in order to investigate the volume changes of rough endoplasmic reticulum (RER), nucleus, mitochondria and autophagosomes. At 2–4 h after stimulation, when the pancreatic cells demonstrated a complete loss of granules, this was accompanied by an increased proportion of autophagosomal activity. This change primarily reflected a greatly increased proportion of profiles retaining autophagic vacuoles containing recognisable cytoplasmic structures such as mitochondria, granule profiles and fragments of RER. The mitochondrial structures reached a significant maximal size 4 h following injection (before degranulation 0.178±0.028 μm3; at 4 h peak value, 0.535±0.109 μm3). Nucleus size showed an early volume increase approaching a maximum value 2 h following degranulation. The regranulation span was thus divided into 3 stages. The first was the membrane remodelling stage (0–2 h). During this period the volume of the RER and secretory granules was greatly decreased. At the intermediate stage (2–4 h) a significant increase of the synthesis zone was observed within the nucleus. The volume of the mitochondria was increasing. At the last step, the major finding was a significant granule accumulation in parallel with an active Golgi zone. PMID:10227666

  12. Roles of AQP5/AQP5-G103D in carbamylcholine-induced volume decrease and in reduction of the activation energy for water transport by rat parotid acinar cells.

    PubMed

    Satoh, Keitaro; Seo, Yoshiteru; Matsuo, Shinsuke; Karabasil, Mileva Ratko; Matsuki-Fukushima, Miwako; Nakahari, Takashi; Hosoi, Kazuo

    2012-10-01

    In order to assess the contribution of the water channel aquaporin-5 (AQP5) to water transport by salivary gland acinar cells, we measured the cell volume and activation energy (E (a)) of diffusive water permeability in isolated parotid acinar cells obtained from AQP5-G103D mutant and their wild-type rats. Immunohistochemistry showed that there was no change induced by carbamylcholine (CCh; 1 μM) in the AQP5 detected in the acinar cells in the wild-type rat. Acinar cells from mutant rats, producing low levels of AQP5 in the apical membrane, showed a minimal increase in the AQP5 due to the CCh. In the wild-type rat, CCh caused a transient swelling of the acinus, followed by a rapid agonist-induced cell shrinkage, reaching a plateau at 30 s. In the mutant rat, the acinus did not swell by CCh challenge, and the agonist-induced cell shrinkage was delayed by 8 s, reaching a transient minimum at around 1 min, and recovered spontaneously even though CCh was persistently present. In the unstimulated wild-type acinar cells, E (a) was 3.4 ± 0.6 kcal mol(-1) and showed no detectable change after CCh stimulation. In the unstimulated mutant acinar cells, high E (a) value (5.9 ± 0.1 kcal mol(-1)) was detected and showed a minimal decrease after CCh stimulation (5.0 ± 0.3 kcal mol(-1)). These results suggested that AQP5 was the main pathway for water transport in the acinar cells and that it was responsible for the rapid agonist-induced acinar cell shrinkage and also necessary to keep the acinar cell volume reduced during the steady secretion in the wild-type rat.

  13. Ae4 (Slc4a9) Anion Exchanger Drives Cl- Uptake-dependent Fluid Secretion by Mouse Submandibular Gland Acinar Cells.

    PubMed

    Peña-Münzenmayer, Gaspar; Catalán, Marcelo A; Kondo, Yusuke; Jaramillo, Yasna; Liu, Frances; Shull, Gary E; Melvin, James E

    2015-04-24

    Transcellular Cl(-) movement across acinar cells is the rate-limiting step for salivary gland fluid secretion. Basolateral Nkcc1 Na(+)-K(+)-2Cl(-) cotransporters play a critical role in fluid secretion by promoting the intracellular accumulation of Cl(-) above its equilibrium potential. However, salivation is only partially abolished in the absence of Nkcc1 cotransporter activity, suggesting that another Cl(-) uptake pathway concentrates Cl(-) ions in acinar cells. To identify alternative molecular mechanisms, we studied mice lacking Ae2 and Ae4 Cl(-)/HCO3 (-) exchangers. We found that salivation stimulated by muscarinic and β-adrenergic receptor agonists was normal in the submandibular glands of Ae2(-/-) mice. In contrast, saliva secretion was reduced by 35% in Ae4(-/-) mice. The decrease in salivation was not related to loss of Na(+)-K(+)-2Cl(-) cotransporter or Na(+)/H(+) exchanger activity in Ae4(-/-) mice but correlated with reduced Cl(-) uptake during β-adrenergic receptor activation of cAMP signaling. Direct measurements of Cl(-)/HCO3 (-) exchanger activity revealed that HCO3 (-)-dependent Cl(-) uptake was reduced in the acinar cells of Ae2(-/-) and Ae4(-/-) mice. Moreover, Cl(-)/HCO3 (-) exchanger activity was nearly abolished in double Ae4/Ae2 knock-out mice, suggesting that most of the Cl(-)/HCO3 (-) exchanger activity in submandibular acinar cells depends on Ae2 and Ae4 expression. In conclusion, both Ae2 and Ae4 anion exchangers are functionally expressed in submandibular acinar cells; however, only Ae4 expression appears to be important for cAMP-dependent regulation of fluid secretion.

  14. Platelet-activating factor promotes motility in breast cancer cells and disrupts non-transformed breast acinar structures.

    PubMed

    Anandi, V Libi; Ashiq, K A; Nitheesh, K; Lahiri, M

    2016-01-01

    A plethora of studies have demonstrated that chronic inflammatory microenvironment influences the genesis and progression of tumors. Such microenvironments are enriched with various lipid mediators. Platelet activating factor (PAF, 1-alkyl-2-acetyl-sn-glycero-3-phosphocholine) is one such lipid mediator that is secreted by different immune cell types during inflammation and by breast cancer cells upon stimulation with growth factors. Overexpression of PAF-receptor has also been observed in many other cancers. Here we report the possible roles of PAF in tumor initiation and progression. MCF10A, a non-transformed and non-malignant mammary epithelial cell line, when grown as 3D 'on-top' cultures form spheroids that have a distinct hollow lumen surrounded by a monolayer of epithelial cells. Exposure of these spheroids to PAF resulted in the formation of large deformed acinar structures with disrupted lumen, implying transformation. We then examined the response of transformed cells such as MDA-MB 231 to stimulation with PAF. We observed collective cell migration as well as motility at the single cell level on PAF induction, suggesting its role during metastasis. This increase in collective cell migration is mediated via PI3-kinase and/or JNK pathway and is independent of the MAP-kinase pathway. Taken together this study signifies a novel role of PAF in inducing transformation of non-tumorigenic cells and the vital role in promotion of breast cancer cell migration. PMID:26531049

  15. Formation of post-confluence structure in human parotid gland acinar cells on PLGA through regulation of E-cadherin.

    PubMed

    Chan, Yen-Hui; Huang, Tsung-Wei; Chou, Ya-Shuan; Hsu, Sheng-Hao; Su, Wei-Fang; Lou, Pei-Jen; Young, Tai-Horng

    2012-01-01

    As a potential solution for patients to retrieve their lost salivary gland functions, tissue engineering of an auto-secretory device is profoundly needed. Under serum-free environment, primary human parotid gland acinar (PGAC) cells can be obtained. After reaching confluence, PGAC cells spontaneously form three-dimension (3D) cell aggregations, termed post-confluence structure (PCS), and change their behaviors. Poly (lactic-co-glycolic acid) (PLGA) has been widely used in the field of biomedical applications because of its biodegradable properties for desired functions. Nonetheless, the role of PLGA in facilitating PGAC cells to form PCS has seldom been explored to recover epithelial characteristics. In this study, PGAC cells were found to have a greater tendency to form PCS on PLGA than on tissue culture polystyrene (TCPS). By tracing cell migration paths and modulating E-cadherin activity with specific inhibitor or antibody, we demonstrated that the static force of homophilic interaction on surfaces of individual cells, but not the dynamics of cell migration, played a more important role in PCS formation. Thus, PLGA was successfully confirmed to support PGAC cells to form more PCS through the effects on enhancing E-cadherin expression, which is associated with FAK/ILK/Snail expression in PGAC cells. This result indicates that selective appropriate biomaterials may be potentially useful in generating 3D PCS on two-dimension (2D) substrate without fabricating a complex 3D scaffold.

  16. Acinar autolysis and mucous extravasation in human sublingual glands: a microscopic postmortem study

    PubMed Central

    AZEVEDO-ALANIS, Luciana Reis; TOLENTINO, Elen de Souza; de ASSIS, Gerson Francisco; CESTARI, Tânia Mary; LARA, Vanessa Soares; DAMANTE, José Humberto

    2015-01-01

    Although some morphological investigations on aged human sublingual glands (HSG) found eventual phenomena identified as autolysis and mucous extravasation, the exact meaning of these findings has not been elucidated. Objective The aim of this work is to investigate whether acinar autolysis and mucous extravasation are related to the aging process in human sublingual glands. We also speculate if autolytic changes may assist forensic pathologists in determining time of death. Material and Methods 186 cadavers’ glands were allocated to age groups: I (0–30 years); II (31–60), and III (61–90). Time and mode of death were also recorded. Acinar autolysis and mucous extravasation were classified as present or absent. Ultrastructural analysis was performed using transmission electron microscopy (TEM). Data were compared using Mann-Whitney U, Spearman’s correlation coefficient, Kruskal-Wallis, and Dunn tests (p<0.05). Results There was correlation between age and acinar autolysis (r=0.38; p=0.0001). However, there was no correlation between autolysis and time of death. No differences were observed between genders. TEM showed mucous and serous cells presenting nuclear and membrane alterations and mucous cells were more susceptible to autolysis. Conclusion Acinar autolysis occurred in all age groups and increased with age while mucous extravasation was rarely found. Both findings are independent. Autolysis degrees in HSG could not be used to determine time of death. PMID:26537715

  17. Adenovirus-mediated hAQP1 expression in irradiated mouse salivary glands causes recovery of saliva secretion by enhancing acinar cell volume decrease.

    PubMed

    Teos, L Y; Zheng, C-Y; Liu, X; Swaim, W D; Goldsmith, C M; Cotrim, A P; Baum, B J; Ambudkar, I S

    2016-07-01

    Head and neck irradiation (IR) during cancer treatment causes by-stander effects on the salivary glands leading to irreversible loss of saliva secretion. The mechanism underlying loss of fluid secretion is not understood and no adequate therapy is currently available. Delivery of an adenoviral vector encoding human aquaporin-1 (hAQP1) into the salivary glands of human subjects and animal models with radiation-induced salivary hypofunction leads to significant recovery of saliva secretion and symptomatic relief in subjects. To elucidate the mechanism underlying loss of salivary secretion and the basis for AdhAQP1-dependent recovery of salivary gland function we assessed submandibular gland function in control mice and mice 2 and 8 months after treatment with a single 15-Gy dose of IR (delivered to the salivary gland region). Salivary secretion and neurotransmitter-stimulated changes in acinar cell volume, an in vitro read-out for fluid secretion, were monitored. Consistent with the sustained 60% loss of fluid secretion following IR, a carbachol (CCh)-induced decrease in acinar cell volume from the glands of mice post IR was transient and attenuated as compared with that in cells from non-IR age-matched mice. The hAQP1 expression in non-IR mice induced no significant effect on salivary fluid secretion or CCh-stimulated cell volume changes, except in acinar cells from 8-month group where the initial rate of cell shrinkage was increased. Importantly, the expression of hAQP1 in the glands of mice post IR induced recovery of salivary fluid secretion and a volume decrease in acinar cells to levels similar to those in cells from non-IR mice. The initial rates of CCh-stimulated cell volume reduction in acinar cells from hAQP1-expressing glands post IR were similar to those from control cells. Altogether, the data suggest that expression of hAQP1 increases the water permeability of acinar cells, which underlies the recovery of fluid secretion in the salivary glands

  18. Adenovirus-mediated hAQP1 expression in irradiated mouse salivary glands causes recovery of saliva secretion by enhancing acinar cell volume decrease.

    PubMed

    Teos, L Y; Zheng, C-Y; Liu, X; Swaim, W D; Goldsmith, C M; Cotrim, A P; Baum, B J; Ambudkar, I S

    2016-07-01

    Head and neck irradiation (IR) during cancer treatment causes by-stander effects on the salivary glands leading to irreversible loss of saliva secretion. The mechanism underlying loss of fluid secretion is not understood and no adequate therapy is currently available. Delivery of an adenoviral vector encoding human aquaporin-1 (hAQP1) into the salivary glands of human subjects and animal models with radiation-induced salivary hypofunction leads to significant recovery of saliva secretion and symptomatic relief in subjects. To elucidate the mechanism underlying loss of salivary secretion and the basis for AdhAQP1-dependent recovery of salivary gland function we assessed submandibular gland function in control mice and mice 2 and 8 months after treatment with a single 15-Gy dose of IR (delivered to the salivary gland region). Salivary secretion and neurotransmitter-stimulated changes in acinar cell volume, an in vitro read-out for fluid secretion, were monitored. Consistent with the sustained 60% loss of fluid secretion following IR, a carbachol (CCh)-induced decrease in acinar cell volume from the glands of mice post IR was transient and attenuated as compared with that in cells from non-IR age-matched mice. The hAQP1 expression in non-IR mice induced no significant effect on salivary fluid secretion or CCh-stimulated cell volume changes, except in acinar cells from 8-month group where the initial rate of cell shrinkage was increased. Importantly, the expression of hAQP1 in the glands of mice post IR induced recovery of salivary fluid secretion and a volume decrease in acinar cells to levels similar to those in cells from non-IR mice. The initial rates of CCh-stimulated cell volume reduction in acinar cells from hAQP1-expressing glands post IR were similar to those from control cells. Altogether, the data suggest that expression of hAQP1 increases the water permeability of acinar cells, which underlies the recovery of fluid secretion in the salivary glands

  19. Effect of the cigarette smoke component, 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK), on physiological and molecular parameters of thiamin uptake by pancreatic acinar cells.

    PubMed

    Srinivasan, Padmanabhan; Subramanian, Veedamali S; Said, Hamid M

    2013-01-01

    Thiamin is indispensable for the normal function of pancreatic acinar cells. These cells take up thiamin via specific carrier-mediated process that involves thiamin transporter-1 and -2 (THTR-1 and THTR-2; products of SLC19A2 and SLC19A3 genes, respectively). In this study we examined the effect of chronic exposure of pancreatic acinar cells in vitro (pancreatic acinar 266-6 cells) and in vivo (wild-type and transgenic mice carrying the SLC19A2 and SLC19A3 promoters) to the cigarette smoke component 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) on physiological and molecular parameters of the thiamin uptake process. The results show that chronic exposure of 266-6 cells to NNK (3 µM, 24 h) leads to a significant inhibition in thiamin uptake. The inhibition was associated with a significant decrease in the level of expression of THTR-1 and -2 at the protein and mRNA levels as well as in the activity of SLC19A2 and SLC19A3 promoters. Similarly chronic exposure of mice to NNK (IP 10 mg/100 g body weight, three times/week for 2 weeks) leads to a significant inhibition in thiamin uptake by freshly isolated pancreatic acinar cells, as well as in the level of expression of THTR-1 and -2 protein and mRNA. Furthermore, activity of the SLC19A2 and SLC19A3 promoters expressed in transgenic mice were significantly suppressed by chronic exposure to NNK. The effect of NNK on the activity of the SLC19A2 and SLC19A3 promoters was not mediated via changes in their methylation profile, rather it appears to be exerted via an SP1/GG and SP1/GC cis-regulatory elements in these promoters, respectively. These results demonstrate, for the first time, that chronic exposure of pancreatic acinar cells to NNK negatively impacts the physiological and molecular parameters of thiamin uptake by pancreatic acinar cells and that this effect is exerted, at least in part, at the level of transcription of the SLC19A2 and SLC19A3 genes.

  20. Programmed cell death in protists.

    PubMed

    Deponte, Marcel

    2008-07-01

    Programmed cell death in protists does not seem to make sense at first sight. However, apoptotic markers in unicellular organisms have been observed in all but one of the six/eight major groups of eukaryotes suggesting an ancient evolutionary origin of this regulated process. This review summarizes the available data on apoptotic markers in non-opisthokonts and elucidates potential functions and evolution of programmed cell death. A newly discovered family of caspase-like proteases, the metacaspases, is considered to exert the function of caspases in unicellular organisms. Important results on metacaspases, however, showed that they cannot be always correlated to the measured proteolytic activity during protist cell death. Thus, a major challenge for apoptosis research in a variety of protists remains the identification of the molecular cell death machinery.

  1. Protein kinase C expression in salivary gland acinar epithelial cells in non-obese diabetic mice, an experimental model for Sjögren's syndrome.

    PubMed

    Tensing, E-K; Ma, J; Hukkanen, M; Fox, H S; Li, T-F; Törnwall, J; Konttinen, Y T

    2005-01-01

    We planned to investigate the expression of protein kinase C (PKC) isoforms in acinar epithelial cells of salivary glands in the non-obese diabetic (NOD) mouse to find out if they develop changes of the PKC system like those seen in the human counterpart, i.e. in Sjögren's syndrome. Parotid, submandibular, and sublingual glands from NOD and control BALB/c mice were stained with a panel of monoclonal antibodies directed against conventional (alpha, beta, and gamma), novel (delta, epsilon, and theta), and atypical (lambda and iota) PKC isoforms using the streptavidin/HRP method. Similarly to human labial salivary glands, acinar epithelial cells of the healthy control BALB/c mice contained two of the conventional PKC isoforms, alpha and beta. Acinar and ductal epithelial cells also contained the atypical PKC isoforms lambda and iota. PKC isoforms gamma, delta, epsilon, and theta were not found. NOD mice which displayed focal sialadenitis contained the same conventional and atypical PKC isoforms. The acinar cells in NOD mice, in contrast to the Sjögren's syndrome patients, did not lack PKC alpha or beta. On the contrary, PKC alpha and beta staining was stronger than in the control BALB/c mice. The present results demonstrate that both conventional and atypical PKC isoforms participate in the salivary epithelial cell biology and that there are mouse strain-associated and/or disease state-associated changes in their expression. The lack of PKC alpha and beta isoforms found in Sjögren's syndrome was not reproduced in NOD mice, which discloses one more difference between the human disease and its NOD mouse model.

  2. Somatostatin receptors on rat pancreatic acinar cells. Pharmacological and structural characterization and demonstration of down-regulation in streptozotocin diabetes.

    PubMed

    Srikant, C B; Patel, Y C

    1986-06-15

    The binding of somatostatin-14 (S-14) to rat pancreatic acinar cell membranes was characterized using [125I-Tyr11]S-14 as the radioligand. Maximum binding was observed at pH 7.4 and was Ca2+-dependent. Such Ca2+ dependence of S-14 receptor binding was not observed in other tissues. Scatchard analysis of the competitive inhibition by S-14 of [125I-Tyr11]S-14 binding revealed a single class of high affinity sites (Kd = 0.5 +/- 0.07 nM) with a binding capacity (Bmax) of 266 +/- 22 fmol/mg of protein. [D-Trp8]S-14 and structural analogs with halogenated Trp moiety exhibited 2-32-fold greater binding affinity than S-14, [D-F5-Trp8]S-14 being the most potent. [Tyr11]S-14 was equipotent with S-14. The affinity of somatostatin-28 for binding to these receptors was 50% of that of S-14. Cholecystokinin octapeptide (CCK-8) inhibited the binding of [125I-Tyr11]S-14, but its inhibition curve was not parallel to that of S-14. In the presence of 1 nM CCK-8, the Bmax of S-14 receptors was reduced to 150 +/- 17 fmol/mg of protein. Dibutyryl cyclic GMP, a CCK receptor antagonist, partially reversed the inhibitory action of CCK-8, suggesting that CCK receptors mediate the inhibition of S-14 receptor binding. GDP, GTP, and guanyl-5'-yl imidodiphosphate inhibit S-14 receptor binding in this tissue. The inhibition was shown to be due to decrease in binding capacity and not due to change in affinity. Specifically bound [125I-Tyr11]S-14 cross-linked to the S-14 receptors was found associated with three proteins of approximate Mr = 200,000, 80,000, and 70,000 which could be detected under both reducing and nonreducing conditions. Finally, pancreatic acinar cell S-14 receptors were shown to be down-regulated by persistent hypersomatostatinemia 1 week after streptozotocin-induced diabetes characterized by decreased Bmax (105 +/- 13 fmol/mg of protein) without any change in affinity. We conclude that pancreatic acinar cell membrane S-14 receptors require Ca2+ for maximal binding and thus

  3. Successful Salvage Chemotherapy with FOLFIRINOX for Recurrent Mixed Acinar Cell Carcinoma and Ductal Adenocarcinoma of the Pancreas in an Adolescent Patient

    PubMed Central

    Pfrommer, Sarah; Weber, Achim; Dutkowski, Philipp; Schäfer, Niklaus G.; Müllhaupt, Beat; Bourquin, Jean-Pierre; Breitenstein, Stefan; Pestalozzi, Bernhard C.; Stenner, Frank; Renner, Christoph; D'Addario, Giannicola; Graf, Hans-Jörg; Knuth, Alexander; Clavien, Pierre-Alain; Samaras, Panagiotis

    2013-01-01

    Pancreatic tumors are rare in children and adolescents. Here, we report the case of a 15-year-old boy who presented with a mixed acinar cell carcinoma/ductal adenocarcinoma with blastomatous components. He received multimodal treatment including various chemotherapy regimens and multistep surgery including liver transplantation. Introduction of FOLFIRINOX after relapse repeatedly achieved a durable metabolic and clinical response with good quality of life. PMID:24163668

  4. Successful Salvage Chemotherapy with FOLFIRINOX for Recurrent Mixed Acinar Cell Carcinoma and Ductal Adenocarcinoma of the Pancreas in an Adolescent Patient.

    PubMed

    Pfrommer, Sarah; Weber, Achim; Dutkowski, Philipp; Schäfer, Niklaus G; Müllhaupt, Beat; Bourquin, Jean-Pierre; Breitenstein, Stefan; Pestalozzi, Bernhard C; Stenner, Frank; Renner, Christoph; D'Addario, Giannicola; Graf, Hans-Jörg; Knuth, Alexander; Clavien, Pierre-Alain; Samaras, Panagiotis

    2013-01-01

    Pancreatic tumors are rare in children and adolescents. Here, we report the case of a 15-year-old boy who presented with a mixed acinar cell carcinoma/ductal adenocarcinoma with blastomatous components. He received multimodal treatment including various chemotherapy regimens and multistep surgery including liver transplantation. Introduction of FOLFIRINOX after relapse repeatedly achieved a durable metabolic and clinical response with good quality of life. PMID:24163668

  5. Leptin protection of salivary gland acinar cells against ethanol cytotoxicity involves Src kinase-mediated parallel activation of prostaglandin and constitutive nitric oxide synthase pathways.

    PubMed

    Slomiany, B L; Slomiany, A

    2008-04-01

    Leptin, a pleiotropic cytokine secreted by adipocytes but also identified in salivary glands and saliva, is recognized as an important element of oral mucosal defense. Here, we report that in sublingual salivary glands leptin protects the acinar cells of against ethanol cytotoxicity. We show that ethanol- induced cytotoxicity, characterized by a marked drop in the acinar cell capacity for NO production, arachidonic acid release and prostaglandin generation, was subject to suppression by leptin. The loss in countering capacity of leptin on the ethanol-induced cytotoxicity was attained with cyclooxygenase inhibitor, indomethacin and nitric oxide synthase (cNOS) inhibitor, L-NAME, as well as PP2, an inhibitor of Src kinase. Indomethacin, while not affecting leptin-induced arachidonic acid release, caused the inhibition in PGE2 generation, pretreatment with L-NAME led to the inhibition in NO production, whereas PP2 exerted the inhibitory effect on leptin-induced changes in NO, arachidonic acid, and PGE2. The leptin-induced changes in arachidonic acid release and PGE2 generation were blocked by ERK inhibitor, PD98059, but not by PI3K inhibitor, wortmannin. Further, leptin suppression of ethanol cytotoxicity was reflected in the increased Akt and cNOS phosphorylation that was sensitive to PP2. Moreover, the stimulatory effect of leptin on the acinar cell cNOS activity was inhibited not only by PP2, but also by Akt inhibitor, SH-5, while wortmannin had no effect. Our findings demonstrate that leptin protection of salivary gland acinar cells against ethanol cytotoxicity involves Src kinase-mediated parallel activation of MAPK/ERK and Akt that result in up-regulation of the respective prostaglandin and nitric oxide synthase pathways.

  6. Caspase-independent cell deaths.

    PubMed

    Lockshin, Richard A; Zakeri, Zahra

    2002-12-01

    A very common and the best understood of the mechanisms of physiological cell death is apoptosis, resulting from the activation, through either of two primary pathways, of site-specific proteases called caspases. There are, however, many other routes to cell death, prominently including autophagy and proteasomal degradation of critical constituents of cells. These routes are frequently seen in experimental situations in which initiator or effector caspases are inhibited or blocked through genetic means, but they are also encountered during normal physiological and pathological processes. Most frequently, autophagic or proteasomal degradation is used to eliminate massive cytoplasm of very large cells, especially post-mitotic cells, and these pathways are prominent even though caspase genes, messages, and pro-enzymes are found in the cells. These forms of cell death are fully physiological and not simply a default pathway for a defective cell; and they are distinct from necrosis. We do not yet understand the extent to which the pathways are linked, what mechanisms trigger the caspase-independent deaths, and how the choices are made.

  7. Regulated cell death in AKI.

    PubMed

    Linkermann, Andreas; Chen, Guochun; Dong, Guie; Kunzendorf, Ulrich; Krautwald, Stefan; Dong, Zheng

    2014-12-01

    AKI is pathologically characterized by sublethal and lethal damage of renal tubules. Under these conditions, renal tubular cell death may occur by regulated necrosis (RN) or apoptosis. In the last two decades, tubular apoptosis has been shown in preclinical models and some clinical samples from patients with AKI. Mechanistically, apoptotic cell death in AKI may result from well described extrinsic and intrinsic pathways as well as ER stress. Central converging nodes of these pathways are mitochondria, which become fragmented and sensitized to membrane permeabilization in response to cellular stress, resulting in the release of cell death-inducing factors. Whereas apoptosis is known to be regulated, tubular necrosis was thought to occur by accident until recent work unveiled several RN subroutines, most prominently receptor-interacting protein kinase-dependent necroptosis and RN induced by mitochondrial permeability transition. Additionally, other cell death pathways, like pyroptosis and ferroptosis, may also be of pathophysiologic relevance in AKI. Combination therapy targeting multiple cell-death pathways may, therefore, provide maximal therapeutic benefits. PMID:24925726

  8. Glutathione in Cancer Cell Death

    PubMed Central

    Ortega, Angel L.; Mena, Salvador; Estrela, Jose M.

    2011-01-01

    Glutathione (L-γ-glutamyl-L-cysteinyl-glycine; GSH) in cancer cells is particularly relevant in the regulation of carcinogenic mechanisms; sensitivity against cytotoxic drugs, ionizing radiations, and some cytokines; DNA synthesis; and cell proliferation and death. The intracellular thiol redox state (controlled by GSH) is one of the endogenous effectors involved in regulating the mitochondrial permeability transition pore complex and, in consequence, thiol oxidation can be a causal factor in the mitochondrion-based mechanism that leads to cell death. Nevertheless GSH depletion is a common feature not only of apoptosis but also of other types of cell death. Indeed rates of GSH synthesis and fluxes regulate its levels in cellular compartments, and potentially influence switches among different mechanisms of death. How changes in gene expression, post-translational modifications of proteins, and signaling cascades are implicated will be discussed. Furthermore, this review will finally analyze whether GSH depletion may facilitate cancer cell death under in vivo conditions, and how this can be applied to cancer therapy. PMID:24212662

  9. Pancreatic Fat Accumulation, Fibrosis, and Acinar Cell Injury in the Zucker Diabetic Fatty Rat Fed a Chronic High-Fat Diet

    PubMed Central

    Matsuda, Akiko; Makino, Naohiko; Tozawa, Tomohiro; Shirahata, Nakao; Honda, Teiichiro; Ikeda, Yushi; Sato, Hideyuki; Ito, Miho; Kakizaki, Yasuharu; Akamatsu, Manabu; Ueno, Yoshiyuki; Kawata, Sumio

    2014-01-01

    Objective The histological alteration of the exocrine pancreas in obesity has not been clarified. In the present study, we investigated biochemical and histological changes in the exocrine pancreas of obese model rats. Methods Zucker lean rats were fed a standard diet, and Zucker diabetic fatty (ZDF) rats were divided into 2 groups fed a standard diet and a high-fat diet, respectively. These experimental groups were fed each of the diets from 6 weeks until 12, 18, 24 weeks of age. We performed blood biochemical assays and histological analysis of the pancreas. Results In the ZDF rats fed a high-fat diet, the ratio of accumulated pancreatic fat area relative to exocrine gland area was increased significantly at 18 weeks of age in comparison with the other 2 groups (P < 0.05), and lipid droplets were observed in acinar cells. Subsequently, at 24 weeks of age in this group, pancreatic fibrosis and the serum exocrine pancreatic enzyme levels were increased significantly relative to the other 2 groups (P < 0.01). Conclusions In ZDF rats fed a chronic high-fat diet, fat accumulates in pancreatic acinar cells, and this fatty change seems to be related to subsequent pancreatic fibrosis and acinar cell injury. PMID:24717823

  10. SGLT1 protein expression in plasma membrane of acinar cells correlates with the sympathetic outflow to salivary glands in diabetic and hypertensive rats.

    PubMed

    Sabino-Silva, Robinson; Alves-Wagner, Ana B T; Burgi, Katia; Okamoto, Maristela M; Alves, Adilson S; Lima, Guilherme A; Freitas, Helayne S; Antunes, Vagner R; Machado, Ubiratan F

    2010-12-01

    Salivary gland dysfunction is a feature in diabetes and hypertension. We hypothesized that sodium-glucose cotransporter 1 (SGLT1) participates in salivary dysfunctions through a sympathetic- and protein kinase A (PKA)-mediated pathway. In Wistar-Kyoto (WKY), diabetic WKY (WKY-D), spontaneously hypertensive (SHR), and diabetic SHR (SHR-D) rats, PKA/SGLT1 proteins were analyzed in parotid and submandibular glands, and the sympathetic nerve activity (SNA) to the glands was monitored. Basal SNA was threefold higher in SHR (P < 0.001 vs. WKY), and diabetes decreased this activity (∼50%, P < 0.05) in both WKY and SHR. The catalytic subunit of PKA and the plasma membrane SGLT1 content in acinar cells were regulated in parallel to the SNA. Electrical stimulation of the sympathetic branch to salivary glands increased (∼30%, P < 0.05) PKA and SGLT1 expression. Immunohistochemical analysis confirmed the observed regulations of SGLT1, revealing its location in basolateral membrane of acinar cells. Taken together, our results show highly coordinated regulation of sympathetic activity upon PKA activity and plasma membrane SGLT1 content in salivary glands. Furthermore, the present findings show that diabetic- and/or hypertensive-induced changes in the sympathetic activity correlate with changes in SGLT1 expression in basolateral membrane of acinar cells, which can participate in the salivary glands dysfunctions reported by patients with these pathologies.

  11. RAS inhibitors decrease apoptosis of acinar cells and increase elimination of pancreatic stellate cells after in the course of experimental chronic pancreatitis induced by dibutyltin dichloride.

    PubMed

    Madro, A; Korolczuk, A; Czechowska, G; Celiński, K; Słomka, M; Prozorow-Król, B; Korobowicz, E

    2008-08-01

    Chronic pancreatitis (CP) is a progressive disease, in which the exocrine function of the gland is gradually lost and fibrosis develops due to repeated episodes of acute pancreatitis. The aim of the study was to investigate the effects of RAS inhibitors on the apoptosis of acinar cells and pancreatic stellate cells (PSCs) elimination in experimental CP induced by dibutyltin dichloride (DBTC). CP was induced by administration of DBTC to the femoral vein. Simultaneously captopril, losartan, enalapril and lisinopril were administered intraperitoneally. The rats were decapitated after 60 days and tissue of pancreas was collected. In rats treated by DBTC the features of inflammatory infiltration, ductal lumen dilatation, fibrosis were found. Strong reactivity with caspase2(L) and clusterin-beta antibodies was observed in areas of fibrosis. In animals treated with RAS inhibitors inflammatory changes and fibrosis were less severe. In groups of rats treated with DBTC and RAS inhibitors immunoreactivity of caspase(2L) and clusterin-beta was weak. Positive immunostaining against smooth muscle actine and desmin was observed in the elongated cells (PSC-s). This reaction was weak in groups of rat treated with DBTC and RAS inhibitors. Treatment of CP rats with RAS inhibitors alleviate apoptosis of pancreatic acinar cells and induces PSCs elimination. PMID:18812642

  12. Cell Death in Genome Evolution

    PubMed Central

    Teng, Xinchen; Hardwick, J. Marie

    2015-01-01

    Inappropriate survival of abnormal cells underlies tumorigenesis. Most discoveries about programmed cell death have come from studying model organisms. Revisiting the experimental contexts that inspired these discoveries helps explain confounding biases that inevitably accompany such discoveries. Amending early biases has added a newcomer to the collection of cell death models. Analysis of gene-dependent death in yeast revealed the surprising influence of single gene mutations on subsequent eukaryotic genome evolution. Similar events may influence the selection for mutations during early tumorigenesis. The possibility that an early random mutation might drive the selection for a cancer driver mutation is conceivable but difficult to demonstrate. This was tested in yeast, revealing that mutation of almost any gene appears to specify the selection for a new second mutation. Some human tumors contain pairs of mutant genes homologous to co-occurring mutant genes in yeast. Here we consider how yeast again provide novel insights into tumorigenesis. PMID:25725369

  13. Pancreatic β Cell Mass Death

    PubMed Central

    Marrif, Husnia I.; Al-Sunousi, Salma I.

    2016-01-01

    Type two diabetes (T2D) is a challenging metabolic disorder for which a cure has not yet been found. Its etiology is associated with several phenomena, including significant loss of insulin-producing, beta cellcell) mass via progressive programmed cell death and disrupted cellular autophagy. In diabetes, the etiology of β cell death and the role of mitochondria are complex and involve several layers of mechanisms. Understanding the dynamics of those mechanisms could permit researchers to develop an intervention for the progressive loss of β cells. Currently, diabetes research has shifted toward rejuvenation and plasticity technology and away from the simplified approach of hormonal compensation. Diabetes research is currently challenged by questions such as how to enhance cell survival, decrease apoptosis and replenish β cell mass in diabetic patients. In this review, we discuss evidence that β cell development and mass formation are guided by specific signaling systems, particularly hormones, transcription factors, and growth factors, all of which could be manipulated to enhance mass growth. There is also strong evidence that β cells are dynamically active cells, which, under specific conditions such as obesity, can increase in size and subsequently increase insulin secretion. In certain cases of aggressive or advanced forms of T2D, β cells become markedly impaired, and the only alternatives for maintaining glucose homeostasis are through partial or complete cell grafting (the Edmonton protocol). In these cases, the harvesting of an enriched population of viable β cells is required for transplantation. This task necessitates a deep understanding of the pharmacological agents that affect β cell survival, mass, and function. The aim of this review is to initiate discussion about the important signals in pancreatic β cell development and mass formation and to highlight the process by which cell death occurs in diabetes. This review also examines the

  14. A comparison study of pancreatic acinar cell carcinoma with ductal adenocarcinoma using computed tomography in Chinese patients

    PubMed Central

    Wang, Qingbing; Wang, Xiaolin; Guo, Rongfang; Li, Guoping

    2016-01-01

    Pancreatic acinar cell carcinoma (ACC) is a rare tumor that is difficult to diagnose preoperatively. The aim of this study was to evaluate and describe the computed tomography (CT) features of ACC and compare the results with pancreatic ductal adenocarcinoma (DAC) for improving preoperative diagnosis. The control group consisted of 34 patients with DAC collected from the pathology electronic database. The CT imaging from nine patients with pathologically confirmed ACC was retrospectively reviewed. Two radiologists independently assessed the tumor location, size, texture, and enhancement patterns. We found that 64.3% (9/14) of ACC tumors were homogeneous and 35.7% (5/14) had necrosis. The percentage of common bile duct and pancreatic ductal dilation was 14.3% (2/14) and 7.1% (1/14), respectively. The mean size of ACC was 50.1±24.2 mm. The mean attenuation of ACC was 35.4±3.9 Hounsfield unit (HU) before enhancement, 73.1±42.9 HU in arterial phase, and 71.8±15.6 HU in port venous phase. It is difficult to distinguish ACC from DAC preoperatively only based on CT findings. However, compared with DAC, we found that ACC tumors are likely to be larger and contain more heterogeneous intratumoral necrotic hypovascular regions, and less pancreatic ductal and common biliary dilation. PMID:27660464

  15. A comparison study of pancreatic acinar cell carcinoma with ductal adenocarcinoma using computed tomography in Chinese patients

    PubMed Central

    Wang, Qingbing; Wang, Xiaolin; Guo, Rongfang; Li, Guoping

    2016-01-01

    Pancreatic acinar cell carcinoma (ACC) is a rare tumor that is difficult to diagnose preoperatively. The aim of this study was to evaluate and describe the computed tomography (CT) features of ACC and compare the results with pancreatic ductal adenocarcinoma (DAC) for improving preoperative diagnosis. The control group consisted of 34 patients with DAC collected from the pathology electronic database. The CT imaging from nine patients with pathologically confirmed ACC was retrospectively reviewed. Two radiologists independently assessed the tumor location, size, texture, and enhancement patterns. We found that 64.3% (9/14) of ACC tumors were homogeneous and 35.7% (5/14) had necrosis. The percentage of common bile duct and pancreatic ductal dilation was 14.3% (2/14) and 7.1% (1/14), respectively. The mean size of ACC was 50.1±24.2 mm. The mean attenuation of ACC was 35.4±3.9 Hounsfield unit (HU) before enhancement, 73.1±42.9 HU in arterial phase, and 71.8±15.6 HU in port venous phase. It is difficult to distinguish ACC from DAC preoperatively only based on CT findings. However, compared with DAC, we found that ACC tumors are likely to be larger and contain more heterogeneous intratumoral necrotic hypovascular regions, and less pancreatic ductal and common biliary dilation.

  16. A comparison study of pancreatic acinar cell carcinoma with ductal adenocarcinoma using computed tomography in Chinese patients.

    PubMed

    Wang, Qingbing; Wang, Xiaolin; Guo, Rongfang; Li, Guoping

    2016-01-01

    Pancreatic acinar cell carcinoma (ACC) is a rare tumor that is difficult to diagnose preoperatively. The aim of this study was to evaluate and describe the computed tomography (CT) features of ACC and compare the results with pancreatic ductal adenocarcinoma (DAC) for improving preoperative diagnosis. The control group consisted of 34 patients with DAC collected from the pathology electronic database. The CT imaging from nine patients with pathologically confirmed ACC was retrospectively reviewed. Two radiologists independently assessed the tumor location, size, texture, and enhancement patterns. We found that 64.3% (9/14) of ACC tumors were homogeneous and 35.7% (5/14) had necrosis. The percentage of common bile duct and pancreatic ductal dilation was 14.3% (2/14) and 7.1% (1/14), respectively. The mean size of ACC was 50.1±24.2 mm. The mean attenuation of ACC was 35.4±3.9 Hounsfield unit (HU) before enhancement, 73.1±42.9 HU in arterial phase, and 71.8±15.6 HU in port venous phase. It is difficult to distinguish ACC from DAC preoperatively only based on CT findings. However, compared with DAC, we found that ACC tumors are likely to be larger and contain more heterogeneous intratumoral necrotic hypovascular regions, and less pancreatic ductal and common biliary dilation. PMID:27660464

  17. Regulated Cell Death in AKI

    PubMed Central

    Chen, Guochun; Dong, Guie; Kunzendorf, Ulrich; Krautwald, Stefan

    2014-01-01

    AKI is pathologically characterized by sublethal and lethal damage of renal tubules. Under these conditions, renal tubular cell death may occur by regulated necrosis (RN) or apoptosis. In the last two decades, tubular apoptosis has been shown in preclinical models and some clinical samples from patients with AKI. Mechanistically, apoptotic cell death in AKI may result from well described extrinsic and intrinsic pathways as well as ER stress. Central converging nodes of these pathways are mitochondria, which become fragmented and sensitized to membrane permeabilization in response to cellular stress, resulting in the release of cell death–inducing factors. Whereas apoptosis is known to be regulated, tubular necrosis was thought to occur by accident until recent work unveiled several RN subroutines, most prominently receptor-interacting protein kinase–dependent necroptosis and RN induced by mitochondrial permeability transition. Additionally, other cell death pathways, like pyroptosis and ferroptosis, may also be of pathophysiologic relevance in AKI. Combination therapy targeting multiple cell-death pathways may, therefore, provide maximal therapeutic benefits. PMID:24925726

  18. Transdifferentiation of mouse adipose-derived stromal cells into acinar cells of the submandibular gland using a co-culture system

    SciTech Connect

    Lee, Jingu; Park, Sangkyu; Roh, Sangho

    2015-05-15

    A loss of salivary gland function often occurs after radiation therapy in head and neck tumors, though secretion of saliva by the salivary glands is essential for the health and maintenance of the oral environment. Transplantation of salivary acinar cells (ACs), in part, may overcome the side effects of therapy. Here we directly differentiated mouse adipose-derived stromal cells (ADSCs) into ACs using a co-culture system. Multipotent ADSCs can be easily collected from stromal vascular fractions of adipose tissues. The isolated ADSCs showed positive expression of markers such as integrin beta-1 (CD29), cell surface glycoprotein (CD44), endoglin (CD105), and Nanog. The cells were able to differentiate into adipocytes, osteoblasts, and neural-like cells after 14 days in culture. ADSCs at passage 2 were co-cultured with mouse ACs in AC culture medium using the double-chamber (co-culture system) to avoid mixing the cell types. The ADSCs in this co-culture system expressed markers of ACs, such as α-amylases and aquaporin5, in both mRNA and protein. ADSCs cultured in AC-conditioned medium also expressed AC markers. Cellular proliferation and senescence analyses demonstrated that cells in the co-culture group showed lower senescence and a higher proliferation rate than the AC-conditioned medium group at Days 14 and 21. The results above imply direct conversion of ADSCs into ACs under the co-culture system; therefore, ADSCs may be a stem cell source for the therapy for salivary gland damage. - Highlights: • ADSCs could transdifferentiate into acinar cells (ACs) using ACs co-culture (CCA). • Transdifferentiated ADSCs expressed ACs markers such as α-amylase and aquaporin5. • High proliferation and low senescence were presented in CCA at Day 14. • Transdifferentiation of ADSCs into ACs using CCA may be an appropriate method for cell-based therapy.

  19. Ionizing irradiation induces apoptotic damage of salivary gland acinar cells via NADPH oxidase 1-dependent superoxide generation

    SciTech Connect

    Tateishi, Yoshihisa Sasabe, Eri; Ueta, Eisaku; Yamamoto, Tetsuya

    2008-02-08

    Reactive oxygen species (ROS) have important roles in various physiological processes. Recently, several novel homologues of the phagocytic NADPH oxidase have been discovered and this protein family is now designated as the Nox family. We investigated the involvement of Nox family proteins in ionizing irradiation-induced ROS generation and impairment in immortalized salivary gland acinar cells (NS-SV-AC), which are radiosensitive, and immortalized ductal cells (NS-SV-DC), which are radioresistant. Nox1-mRNA was upregulated by {gamma}-ray irradiation in NS-SV-AC, and the ROS level in NS-SV-AC was increased to approximately threefold of the control level after 10 Gy irradiation. The increase of ROS level in NS-SV-AC was suppressed by Nox1-siRNA-transfection. In parallel with the suppression of ROS generation and Nox1-mRNA expression by Nox1-siRNA, ionizing irradiation-induced apoptosis was strongly decreased in Nox1-siRNA-transfected NS-SV-AC. There were no large differences in total SOD or catalase activities between NS-SV-AC and NS-SV-DC although the post-irradiation ROS level in NS-SV-AC was higher than that in NS-SV-DC. In conclusion, these results indicate that Nox1 plays a crucial role in irradiation-induced ROS generation and ROS-associated impairment of salivary gland cells and that Nox1 gene may be targeted for preservation of the salivary gland function from radiation-induced impairment.

  20. Effects of MeCh, thapsigargin, and La3+ on plasmalemmal and intracellular Ca2+ transport in lacrimal acinar cells.

    PubMed

    Kwan, C Y; Takemura, H; Obie, J F; Thastrup, O; Putney, J W

    1990-06-01

    The Ca2(+)-mobilizing actions of the muscarinic receptor agonist, methacholine (MeCh), and the microsomal Ca2+ pump inhibitor, thapsigargin, were investigated in lacrimal acinar cells. As previously shown for parotid cells (J. Biol. Chem. 264: 12266-12271, 1989), thapsigargin activates both internal Ca2+ release and Ca2+ entry from the extracellular space without increasing cellular inositol phosphates. The inorganic Ca2+ antagonist La3+ inhibited MeCh- or thapsigargin-activated Ca2+ entry. However, when added before MeCh or thapsigargin, La3+ inhibited the extrusion of Ca2+ at the plasma membrane. This phenomenon was exploited in protocols designed to investigate the pathways for filling agonist-sensitive Ca2+ stores in lacrimal cells. The results show that, in contrast to previous suggestions that external Ca2+ is required to replenish agonist-regulated Ca2+ stores, the inhibition of Ca2+ extrusion permits recycling of Ca2+ released by MeCh back into an MeCh- and thapsigargin-sensitive pool. Thus, although extracellular Ca2+ is the major source for refilling the intracellular Ca2+ stores under physiological conditions, the pathway by which this Ca2+ enters the pool need not be a direct one. These results are consistent with the recently revised capacitative model for the refilling of intracellular Ca2+ stores through Ca2+ influx subsequent to Ca2+ depletion, according to which refilling of intracellular Ca2+ stores occurs via a cytoplasmic route rather than a direct channel between intracellular Ca2+ stores and the extracellular space.

  1. Ionizing irradiation induces apoptotic damage of salivary gland acinar cells via NADPH oxidase 1-dependent superoxide generation.

    PubMed

    Tateishi, Yoshihisa; Sasabe, Eri; Ueta, Eisaku; Yamamoto, Tetsuya

    2008-02-01

    Reactive oxygen species (ROS) have important roles in various physiological processes. Recently, several novel homologues of the phagocytic NADPH oxidase have been discovered and this protein family is now designated as the Nox family. We investigated the involvement of Nox family proteins in ionizing irradiation-induced ROS generation and impairment in immortalized salivary gland acinar cells (NS-SV-AC), which are radiosensitive, and immortalized ductal cells (NS-SV-DC), which are radioresistant. Nox1-mRNA was upregulated by gamma-ray irradiation in NS-SV-AC, and the ROS level in NS-SV-AC was increased to approximately threefold of the control level after 10Gy irradiation. The increase of ROS level in NS-SV-AC was suppressed by Nox1-siRNA-transfection. In parallel with the suppression of ROS generation and Nox1-mRNA expression by Nox1-siRNA, ionizing irradiation-induced apoptosis was strongly decreased in Nox1-siRNA-transfected NS-SV-AC. There were no large differences in total SOD or catalase activities between NS-SV-AC and NS-SV-DC although the post-irradiation ROS level in NS-SV-AC was higher than that in NS-SV-DC. In conclusion, these results indicate that Nox1 plays a crucial role in irradiation-induced ROS generation and ROS-associated impairment of salivary gland cells and that Nox1 gene may be targeted for preservation of the salivary gland function from radiation-induced impairment.

  2. Arabidopsis ACCELERATED CELL DEATH2 modulates programmed cell death.

    PubMed

    Yao, Nan; Greenberg, Jean T

    2006-02-01

    The Arabidopsis thaliana chloroplast protein ACCELERATED CELL DEATH2 (ACD2) modulates the amount of programmed cell death (PCD) triggered by Pseudomonas syringae and protoporphyrin IX (PPIX) treatment. In vitro, ACD2 can reduce red chlorophyll catabolite, a chlorophyll derivative. We find that ACD2 shields root protoplasts that lack chlorophyll from light- and PPIX-induced PCD. Thus, chlorophyll catabolism is not obligatory for ACD2 anti-PCD function. Upon P. syringae infection, ACD2 levels and localization change in cells undergoing PCD and in their close neighbors. Thus, ACD2 shifts from being largely in chloroplasts to partitioning to chloroplasts, mitochondria, and, to a small extent, cytosol. ACD2 protects cells from PCD that requires the early mitochondrial oxidative burst. Later, the chloroplasts of dying cells generate NO, which only slightly affects cell viability. Finally, the mitochondria in dying cells have dramatically altered movements and cellular distribution. Overproduction of both ACD2 (localized to mitochondria and chloroplasts) and ascorbate peroxidase (localized to chloroplasts) greatly reduces P. syringae-induced PCD, suggesting a pro-PCD role for mitochondrial and chloroplast events. During infection, ACD2 may bind to and/or reduce PCD-inducing porphyrin-related molecules in mitochondria and possibly chloroplasts that generate reactive oxygen species, cause altered organelle behavior, and activate a cascade of PCD-inducing events.

  3. A betacellulin mutant promotes differentiation of pancreatic acinar AR42J cells into insulin-producing cells with low affinity of binding to ErbB1.

    PubMed

    Nagaoka, Tadahiro; Fukuda, Takayuki; Hashizume, Toshihiro; Nishiyama, Tomoko; Tada, Hiroko; Yamada, Hidenori; Salomon, David S; Yamada, Satoko; Kojima, Itaru; Seno, Masaharu

    2008-06-27

    Betacellulin (BTC) is one of the members of the epidermal growth factor (EGF) ligand family of ErbB receptor tyrosine kinases. It is a differentiation factor as well as a potent mitogen. BTC promotes the differentiation of pancreatic acinar-derived AR42J cells into insulin-producing cells. It independently and preferentially binds to two type I tyrosine kinase receptors, the EGF receptor (ErbB1) and ErbB4. However, the physiochemical characteristics of BTC that are responsible for its preferential binding to these two receptors have not been fully defined. In this study, to investigate the essential amino acid residues of BTC for binding to the two receptors, we introduced point mutations into the EGF domain of BTC employing error-prone PCR. The receptor binding abilities of 190 mutants expressed in Escherichia coli were assessed by enzyme immunoassay. Replacement of the glutamic acid residue at position 88 with a lysine residue in BTC was found to produce a significant loss of affinity for binding to ErbB1, while the affinity of binding to ErbB4 was unchanged. In addition, the mutant of BTC-E/88/K showed less growth-promoting activity on BALB/c 3T3 cells compared with that of the wild-type BTC protein. Interestingly, the BTC mutant protein promoted differentiation of pancreatic acinar AR42J cells at a high frequency into insulin-producing cells compared with AR42J cells that were treated with wild-type BTC protein. These results indicate the possibility of designing BTC mutants, which have an activity of inducing differentiation only, without facilitating growth promotion. PMID:18508082

  4. Damage to pancreatic acinar cells and preservation of islets of Langerhans in a rat model of acute pancreatitis induced by Karwinskia humboldtiana (buckthorn).

    PubMed

    Carcano-Diaz, Katya; Garcia-Garcia, Aracely; Segoviano-Ramirez, Juan Carlos; Rodriguez-Rocha, Humberto; Loera-Arias, Maria de Jesus; Garcia-Juarez, Jaime

    2016-09-01

    Karwinskia humboldtiana (Kh) is a poisonous plant that grows in some regions of the American continent. Consuming large amounts of Kh fruit results in acute intoxication leading to respiratory failure, culminating in death within days. There is evidence of histological damage to the lungs, liver, and kidneys following accidental and experimental Kh intoxication. To date, the microscopic effect of Kh consumption on the pancreas has not been described. We examined the early effects of Kh fruit on pancreatic tissue at different stages of acute intoxication in the Wistar rat. We found progressive damage confined to the exocrine pancreas, starting with a reduction in the number of zymogen granules, loss of acinar architecture, the presence of autophagy-like vesicles, apoptosis and inflammatory infiltrate. The pancreatic pathology culminated in damaged acini characterized by necrosis and edema, with a complete loss of lobular architecture. Interestingly, the morphology of the islets of Langerhans was conserved throughout our evaluations. Taken together, our results indicate the damage induced by a high dose of Kh fruit in the Wistar rat is consistent with an early acute necrotizing pancreatitis that exclusively affects the exocrine pancreas. Therefore, this system might be useful as an animal model to study the treatment of pancreatic diseases. More importantly, as the islets of Langerhans were preserved, the active compounds of Kh fruit could be utilized for the treatment of acinar pancreatic cancer. Further studies might provide insight into the severity of acute Kh intoxication in humans and influence the design of treatments for pancreatic diseases and acinar pancreatic cancer. PMID:26877198

  5. Chronic alcohol exposure affects pancreatic acinar mitochondrial thiamin pyrophosphate uptake: studies with mouse 266-6 cell line and primary cells.

    PubMed

    Srinivasan, Padmanabhan; Nabokina, Svetlana; Said, Hamid M

    2015-11-01

    Thiamin is essential for normal metabolic activity of all mammalian cells, including those of the pancreas. Cells obtain thiamin from their surroundings and enzymatically convert it into thiamin pyrophosphate (TPP) in the cytoplasm; TPP is then taken up by mitochondria via a specific carrier the mitochondrial TPP transporter (MTPPT; product of the SLC25A19 gene). Chronic alcohol exposure negatively impacts the health of pancreatic acinar cells (PAC), but its effect on physiological/molecular parameters of MTPPT is not known. We addressed this issue using mouse pancreatic acinar tumor cell line 266-6 and primary PAC of wild-type and transgenic mice carrying the SLC25A19 promoter that were fed alcohol chronically. Chronic alcohol exposure of 266-6 cells (but not to its nonoxidative metabolites ethyl palmitate and ethyl oleate) led to a significant inhibition in mitochondrial TPP uptake, which was associated with a decreased expression of MTPPT protein, mRNA, and activity of the SLC25A19 promoter. Similarly, chronic alcohol feeding of mice led to a significant inhibition in expression of MTPPT protein, mRNA, heterogeneous nuclear RNA, as well as in activity of SLC25A19 promoter in PAC. While chronic alcohol exposure did not affect DNA methylation of the Slc25a19 promoter, a significant decrease in histone H3 euchromatin markers and an increase in H3 heterochromatin marker were observed. These findings show, for the first time, that chronic alcohol exposure negatively impacts pancreatic MTPPT, and that this effect is exerted, at least in part, at the level of Slc25a19 transcription and appears to involve epigenetic mechanism(s).

  6. Chronic Nicotine Exposure In Vivo and In Vitro Inhibits Vitamin B1 (Thiamin) Uptake by Pancreatic Acinar Cells.

    PubMed

    Srinivasan, Padmanabhan; Thrower, Edwin C; Loganathan, Gopalakrishnan; Balamurugan, A N; Subramanian, Veedamali S; Gorelick, Fred S; Said, Hamid M

    2015-01-01

    Thiamin (vitamin B1), a member of the water-soluble family of vitamins, is essential for normal cellular functions; its deficiency results in oxidative stress and mitochondrial dysfunction. Pancreatic acinar cells (PAC) obtain thiamin from the circulation using a specific carrier-mediated process mediated by both thiamin transporters -1 and -2 (THTR-1 and THTR-2; encoded by the SLC19A2 and SLC19A3 genes, respectively). The aim of the current study was to examine the effect of chronic exposure of mouse PAC in vivo and human PAC in vitro to nicotine (a major component of cigarette smoke that has been implicated in pancreatic diseases) on thiamin uptake and to delineate the mechanism involved. The results showed that chronic exposure of mice to nicotine significantly inhibits thiamin uptake in murine PAC, and that this inhibition is associated with a marked decrease in expression of THTR-1 and THTR-2 at the protein, mRNA and hnRNAs level. Furthermore, expression of the important thiamin-metabolizing enzyme, thiamin pyrophosphokinase (TPKase), was significantly reduced in PAC of mice exposed to nicotine. Similarly, chronic exposure of cultured human PAC to nicotine (0.5 μM, 48 h) significantly inhibited thiamin uptake, which was also associated with a decrease in expression of THTR-1 and THTR-2 proteins and mRNAs. This study demonstrates that chronic exposure of PAC to nicotine impairs the physiology and the molecular biology of the thiamin uptake process. Furthermore, the study suggests that the effect is, in part, mediated through transcriptional mechanism(s) affecting the SLC19A2 and SLC19A3 genes.

  7. Chronic Nicotine Exposure In Vivo and In Vitro Inhibits Vitamin B1 (Thiamin) Uptake by Pancreatic Acinar Cells

    PubMed Central

    Srinivasan, Padmanabhan; Thrower, Edwin C.; Loganathan, Gopalakrishnan; Balamurugan, A. N.; Subramanian, Veedamali S.; Gorelick, Fred S.; Said, Hamid M.

    2015-01-01

    Thiamin (vitamin B1), a member of the water-soluble family of vitamins, is essential for normal cellular functions; its deficiency results in oxidative stress and mitochondrial dysfunction. Pancreatic acinar cells (PAC) obtain thiamin from the circulation using a specific carrier-mediated process mediated by both thiamin transporters -1 and -2 (THTR-1 and THTR-2; encoded by the SLC19A2 and SLC19A3 genes, respectively). The aim of the current study was to examine the effect of chronic exposure of mouse PAC in vivo and human PAC in vitro to nicotine (a major component of cigarette smoke that has been implicated in pancreatic diseases) on thiamin uptake and to delineate the mechanism involved. The results showed that chronic exposure of mice to nicotine significantly inhibits thiamin uptake in murine PAC, and that this inhibition is associated with a marked decrease in expression of THTR-1 and THTR-2 at the protein, mRNA and hnRNAs level. Furthermore, expression of the important thiamin-metabolizing enzyme, thiamin pyrophosphokinase (TPKase), was significantly reduced in PAC of mice exposed to nicotine. Similarly, chronic exposure of cultured human PAC to nicotine (0.5 μM, 48 h) significantly inhibited thiamin uptake, which was also associated with a decrease in expression of THTR-1 and THTR-2 proteins and mRNAs. This study demonstrates that chronic exposure of PAC to nicotine impairs the physiology and the molecular biology of the thiamin uptake process. Furthermore, the study suggests that the effect is, in part, mediated through transcriptional mechanism(s) affecting the SLC19A2 and SLC19A3 genes. PMID:26633299

  8. Source of /sup 3/H-labeled inositol bis- and monophosphates in agonist-activated rat parotid acinar cells

    SciTech Connect

    Hughes, A.R.; Putney, J.W. Jr.

    1989-06-05

    The kinetics of (3H)inositol phosphate metabolism in agonist-activated rat parotid acinar cells were characterized in order to determine the sources of (3H)inositol monophosphates and (3H)inositol bisphosphates. The turnover rates of D-myo-inositol 1,4,5-trisphosphate and its metabolites, D-myo-inositol 1,4-bisphosphate and D-myo-inositol 1,3,4-trisphosphate, were examined following the addition of the muscarinic receptor antagonist, atropine, to cholinergically stimulated parotid cells. D-myo-Inositol 1,4,5-trisphosphate declined with a t1/2 of 7.6 +/- 0.7 s, D-myo-inositol 1,3,4-trisphosphate declined with a t1/2 of 8.6 +/- 1.2 min, and D-myo-inositol 1,4-bisphosphate was metabolized with a t1/2 of 6.0 +/- 0.7 min. The sum of the rates of flux through D-myo-inositol 1,4-bisphosphate and D-myo-inositol 1,3,4-trisphosphate (2.54% phosphatidylinositol/min) did not exceed the calculated rate of breakdown of D-myo-inositol 1,4,5-trisphosphate (2.76% phosphatidylinositol/min). Thus, there is no evidence for the direct hydrolysis of phosphatidylinositol 4-phosphate in intact cells since D-myo-inositol 1,4-bisphosphate formation can be attributed to the dephosphorylation of D-myo-inositol 1,4,5-trisphosphate. The source of the (3H)inositol monophosphates also was examined in cholinergically stimulated parotid cells. When parotid cells were stimulated with methacholine, D-myo-inositol 1,4,5-trisphosphate, D-myo-inositol 1,3,4,5-tetrakisphosphate, D-myo-inositol 1,4-bisphosphate, and D-myo-inositol 4-monophosphate levels increased within 2 s, whereas D-myo-inositol 1-monophosphate accumulation was delayed by several seconds. Rates of (3H)inositol monophosphate accumulation also were examined by the addition of LiCl to cells stimulated to steady state levels of (3H)inositol phosphates.

  9. Regulation of Ca²⁺ release through inositol 1,4,5-trisphosphate receptors by adenine nucleotides in parotid acinar cells.

    PubMed

    Park, Hyung Seo; Betzenhauser, Matthew J; Zhang, Yu; Yule, David I

    2012-01-01

    Secretagogue-stimulated intracellular Ca(2+) signals are fundamentally important for initiating the secretion of the fluid and ion component of saliva from parotid acinar cells. The Ca(2+) signals have characteristic spatial and temporal characteristics, which are defined by the specific properties of Ca(2+) release mediated by inositol 1,4,5-trisphosphate receptors (InsP(3)R). In this study we have investigated the role of adenine nucleotides in modulating Ca(2+) release in mouse parotid acinar cells. In permeabilized cells, the Ca(2+) release rate induced by submaximal [InsP(3)] was increased by 5 mM ATP. Enhanced Ca(2+) release was not observed at saturating [InsP(3)]. The EC(50) for the augmented Ca(2+) release was ∼8 μM ATP. The effect was mimicked by nonhydrolysable ATP analogs. ADP and AMP also potentiated Ca(2+) release but were less potent than ATP. In acini isolated from InsP(3)R-2-null transgenic animals, the rate of Ca(2+) release was decreased under all conditions but now enhanced by ATP at all [InsP(3)]. In addition the EC(50) for ATP potentiation increased to ∼500 μM. These characteristics are consistent with the properties of the InsP(3)R-2 dominating the overall features of InsP(3)R-induced Ca(2+) release despite the expression of all isoforms. Finally, Ca(2+) signals were measured in intact parotid lobules by multiphoton microscopy. Consistent with the release data, carbachol-stimulated Ca(2+) signals were reduced in lobules exposed to experimental hypoxia compared with control lobules only at submaximal concentrations. Adenine nucleotide modulation of InsP(3)R in parotid acinar cells likely contributes to the properties of Ca(2+) signals in physiological and pathological conditions.

  10. Evidence that zymogen granules are not a physiologically relevant calcium pool. Defining the distribution of inositol 1,4,5-trisphosphate receptors in pancreatic acinar cells.

    PubMed

    Yule, D I; Ernst, S A; Ohnishi, H; Wojcikiewicz, R J

    1997-04-01

    A key event leading to exocytosis of pancreatic acinar cell zymogen granules is the inositol 1,4,5-trisphosphate (InsP3)-mediated release of Ca2+ from intracellular stores. Studies using digital imaging microscopy and laser-scanning confocal microscopy have indicated that the initial release of Ca2+ is localized to the apical region of the acinar cell, an area of the cell dominated by secretory granules. Moreover, a recent study has shown that InsP3 is capable of releasing Ca2+ from a preparation enriched in secretory granules (Gerasimenko, O., Gerasimenko, J., Belan, P., and Petersen, O. H., (1996) Cell 84, 473-480). In the present study, we have investigated the possibility that zymogen granules express InsP3 receptors and are thus Ca2+ release sites. Immunofluorescence staining, obtained with antisera specific to types I, II, or III InsP3 receptors and analyzed by confocal fluorescence microscopy revealed that all InsP3 receptor types were present in acinar cells. The type II receptor localized exclusively to an area close to or at the luminal plasma membrane. While types I and III InsP3 receptors displayed a similar luminal distribution, these receptors were also present at low levels in nuclei. The localization of InsP3 receptor was in marked contrast to the distribution of amylase, a zymogen granule content protein. In a zymogen granule fraction prepared in an identical manner to the aforementioned report demonstrating InsP3-induced Ca2+ release, immunoblotting demonstrated the presence of types I, II, and III InsP3 receptors. Ca2+ release from this preparation in response to InsP3, but not thapsigargin, could also be demonstrated. In contrast, when the zymogen granules were further purified on a Percoll gradient, InsP3 receptors were undetectable, and InsP3 failed to release Ca2+. Transmission electron microscopy performed on both preparations showed that the Percoll-purified granule preparation consisted of essentially pure zymogen granules, whereas the

  11. The p21-activated kinase, PAK2, is important in the activation of numerous pancreatic acinar cell signaling cascades and in the onset of early pancreatitis events.

    PubMed

    Nuche-Berenguer, Bernardo; Ramos-Álvarez, Irene; Jensen, R T

    2016-06-01

    In a recent study we explored Group-1-p21-activated kinases (GP.1-PAKs) in rat pancreatic acini. Only PAK2 was present; it was activated by gastrointestinal-hormones/neurotransmitters and growth factors in a PKC-, Src- and small-GTPase-mediated manner. PAK2 was required for enzyme-secretion and ERK/1-2-activation. In the present study we examined PAK2's role in CCK and TPA-activation of important distal signaling cascades mediating their physiological/pathophysiological effects and analyzed its role in pathophysiological processes important in early pancreatitis. In rat pancreatic acini, PAK2-inhibition by the specific, GP.1.PAK-inhibitor, IPA-3-suppressed cholecystokinin (CCK)/TPA-stimulated activation of focal-adhesion kinases and mitogen-activated protein-kinases. PAK2-inhibition reversed the dual stimulatory/inhibitory effect of CCK/TPA on the PI3K/Akt/GSK-3β pathway. However, its inhibition did not affect PKC activation. PAK2-inhibition protected acini from CCK-induced ROS-generation; caspase/trypsin-activation, important in early pancreatitis; as well as from cell-necrosis. Furthermore, PAK2-inhibition reduced proteolytic-activation of PAK-2p34, which is involved in programmed-cell-death. To ensure that the study did not only rely in the specificity of IPA-3 as a PAK inhibitor, we used two other approaches for PAK inhibition, FRAX597 a ATP-competitive-GP.1-PAKs-inhibitor and infection with a PAK2-dominant negative(DN)-Advirus. Those two approaches confirmed the results obtained with IPA-3. This study demonstrates that PAK2 is important in mediating CCK's effect on the activation of signaling-pathways known to mediate its physiological/pathophysiological responses including several cellular processes linked to the onset of pancreatitis. Our results suggest that PAK2 could be a new, important therapeutic target to consider for the treatment of diseases involving deregulation of pancreatic acinar cells. PMID:26912410

  12. Programmed cell death in aging

    PubMed Central

    Tower, John

    2015-01-01

    Programmed cell death (PCD) pathways, including apoptosis and regulated necrosis, are required for normal cell turnover and tissue homeostasis. Mis-regulation of PCD is increasingly implicated in aging and aging-related disease. During aging the cell turnover rate declines for several highly-mitotic tissues. Aging-associated disruptions in systemic and inter-cell signaling combined with cell-autonomous damage and mitochondrial malfunction result in increased PCD in some cell types, and decreased PCD in other cell types. Increased PCD during aging is implicated in immune system decline, skeletal muscle wasting (sarcopenia), loss of cells in the heart, and neurodegenerative disease. In contrast, cancer cells and senescent cells are resistant to PCD, enabling them to increase in abundance during aging. PCD pathways limit life span in fungi, but whether PCD pathways normally limit adult metazoan life span is not yet clear. PCD is regulated by a balance of negative and positive factors, including the mitochondria, which are particularly subject to aging-associated malfunction. PMID:25862945

  13. Cell death in the nervous system

    PubMed Central

    Bredesen, Dale E.; Rao, Rammohan V.; Mehlen, Patrick

    2014-01-01

    Neurodegenerative diseases such as Alzheimer’s disease and Parkinson’s disease trigger neuronal cell death through endogenous suicide pathways. Surprisingly, although the cell death itself may occur relatively late in the course of the degenerative process, the mediators of the underlying cell-death pathways have shown promise as potential therapeutic targets. PMID:17051206

  14. Using pancreas tissue slices for in situ studies of islet of Langerhans and acinar cell biology.

    PubMed

    Marciniak, Anja; Cohrs, Christian M; Tsata, Vasiliki; Chouinard, Julie A; Selck, Claudia; Stertmann, Julia; Reichelt, Saskia; Rose, Tobias; Ehehalt, Florian; Weitz, Jürgen; Solimena, Michele; Slak Rupnik, Marjan; Speier, Stephan

    2014-12-01

    Studies on the cellular function of the pancreas are typically performed in vitro on its isolated functional units, the endocrine islets of Langerhans and the exocrine acini. However, these approaches are hampered by preparation-induced changes of cell physiology and the lack of an intact surrounding. We present here a detailed protocol for the preparation of pancreas tissue slices. This procedure is less damaging to the tissue and faster than alternative approaches, and it enables the in situ study of pancreatic endocrine and exocrine cell physiology in a conserved environment. Pancreas tissue slices facilitate the investigation of cellular mechanisms underlying the function, pathology and interaction of the endocrine and exocrine components of the pancreas. We provide examples for several experimental applications of pancreas tissue slices to study various aspects of pancreas cell biology. Furthermore, we describe the preparation of human and porcine pancreas tissue slices for the validation and translation of research findings obtained in the mouse model. Preparation of pancreas tissue slices according to the protocol described here takes less than 45 min from tissue preparation to receipt of the first slices.

  15. Vasoactive intestinal peptide/vasoactive intestinal peptide receptor relative expression in salivary glands as one endogenous modulator of acinar cell apoptosis in a murine model of Sjögren's syndrome.

    PubMed

    Hauk, V; Calafat, M; Larocca, L; Fraccaroli, L; Grasso, E; Ramhorst, R; Leirós, C Pérez

    2011-12-01

    Sjögren's syndrome (SS) is a chronic autoimmune disease characterized by a progressive oral and ocular dryness that correlates poorly with the autoimmune damage of the glands. It has been proposed that a loss of homeostatic equilibrium in the glands is partly responsible for salivary dysfunction with acinar cells involved actively in the pathogenesis of SS. The non-obese diabetic (NOD) mouse model of Sjögren's syndrome develops secretory dysfunction and early loss of glandular homeostatic mechanisms, with mild infiltration of the glands. Based on the vasodilator, prosecretory and trophic effects of the vasoactive intestinal peptide (VIP) on acini as well as its anti-inflammatory properties we hypothesized that the local expression of VIP/vasoactive intestinal peptide receptor (VPAC) system in salivary glands could have a role in acinar cell apoptosis and macrophage function thus influencing gland homeostasis. Here we show a progressive decline of VIP expression in submandibular glands of NOD mice with no changes in VPAC receptor expression compared with normal mice. The deep loss of endogenous VIP was associated with a loss of acinar cells through apoptotic mechanisms that could be induced further by tumour necrosis factor (TNF)-α and reversed by VIP through a cyclic adenosine-5'-monophosphate (cAMP)/protein kinase A (PKA)-mediated pathway. The clearance of apoptotic acinar cells by macrophages was impaired for NOD macrophages but a shift from inflammatory to regulatory phenotype was induced in macrophages during phagocytosis of apoptotic acinar cells. These results support that the decline in endogenous VIP/VPAC local levels might influence the survival/apoptosis intracellular set point in NOD acinar cells and their clearance, thus contributing to gland homeostasis loss.

  16. Quantitative characterization of the protein contents of the exocrine pancreatic acinar cell by soft x-ray microscopy and advanced digital imaging methods

    SciTech Connect

    Loo Jr., Billy W.

    2000-06-09

    The study of the exocrine pancreatic acinar cell has been central to the development of models of many cellular processes, especially of protein transport and secretion. Traditional methods used to examine this system have provided a wealth of qualitative information from which mechanistic models have been inferred. However they have lacked the ability to make quantitative measurements, particularly of the distribution of protein in the cell, information critical for grounding of models in terms of magnitude and relative significance. This dissertation describes the development and application of new tools that were used to measure the protein content of the major intracellular compartments in the acinar cell, particularly the zymogen granule. Soft x-ray microscopy permits image formation with high resolution and contrast determined by the underlying protein content of tissue rather than staining avidity. A sample preparation method compatible with x-ray microscopy was developed and its properties evaluated. Automatic computerized methods were developed to acquire, calibrate, and analyze large volumes of x-ray microscopic images of exocrine pancreatic tissue sections. Statistics were compiled on the protein density of several organelles, and on the protein density, size, and spatial distribution of tens of thousands of zymogen granules. The results of these measurements, and how they compare to predictions of different models of protein transport, are discussed.

  17. Suppression by Ghrelin of Porphyromonas gingivalis-Induced Constitutive Nitric Oxide Synthase S-Nitrosylation and Apoptosis in Salivary Gland Acinar Cells.

    PubMed

    Slomiany, Bronislaw L; Slomiany, Amalia

    2010-01-01

    Oral mucosal inflammatory responses to periodontopathic bacterium, P. gingivalis, and its key virulence factor, LPS, are characterized by a massive rise in epithelial cell apoptosis and the disturbances in NO signaling pathways. Here, we report that the LPS-induced enhancement in rat sublingual salivary gland acinar cell apoptosis and NO generation was associated with the suppression in constitutive nitric oxide synthase (cNOS) activity and a marked increase in the activity of inducible nitric oxide synthase (iNOS). We demonstrate that the detrimental effect of the LPS on cNOS was manifested by the enzyme protein S-nitrosylation, that was susceptible to inhibition by iNOS inhibitor, 1400 W. Further, we show that a peptide hormone, ghrelin, countered the LPS-induced changes in apoptosis and cNOS activity. This effect of ghrelin was reflected in the decrease in cNOS S-nitrosylation and the increase in phosphorylation. Our findings imply that P. gingivalis-induced disturbances in the acinar cell NO signaling pathways result from upregulation in iNOS-derived NO that causes cNOS S-nitrosylation that interferes with its activation through phosphorylation. We also show that ghrelin protection against P. gingivalis-induced disturbances involves cNOS activation associated with a decrease in its S-nitrosylation and the increase in phosphorylation.

  18. Agonist-sensitive calcium pool in the pancreatic acinar cell. II. Characterization of reloading

    SciTech Connect

    Muallem, S.; Schoeffield, M.S.; Fimmel, C.J.; Pandol, S.J.

    1988-08-01

    45Ca2+ fluxes and free cytosolic Ca2+ measurements in guinea pig pancreatic acini indicated that after agonist stimulation and the release of Ca2+ from the agonist-sensitive pool at least part of the Ca2+ is extruded from the cell, resulting in 45Ca2+ efflux. In the continued presence of agonist, the pool remains permeable to Ca2+ but partially refills with Ca2+. This reloading is dependent on the concentration of extracellular Ca2+. In the absence of extracellular Ca2+, the pool is completely depleted of Ca2+. However, with increasing concentrations of CaCl2 in the incubation solution (from 0.5 to 2.0 mM) there is increasing repletion of the pool with Ca2+ during agonist stimulation. With termination of agonist stimulation, the Ca2+ permeability of the agonist-sensitive pool is rapidly reduced to that measured in the unstimulated cell. As a result, the Ca2+ incorporated into the pool during the stimulation period is rapidly trapped within the pool and exchanges poorly with medium Ca2+. Subsequently, the pool completely refills with Ca2+. The rate of Ca2+ reloading at the termination of agonist stimulation is slower than the conversion of the pool to the impermeable state. In incubation media containing 1.3 mM CaCl2, the half-time for reloading at the termination of stimulation is 5 min. These observations demonstrate the characteristics of Ca2+ reloading of the agonist-sensitive pool both during stimulation and at the termination of stimulation.

  19. Pathogen Tactics to Manipulate Plant Cell Death.

    PubMed

    Mukhtar, M Shahid; McCormack, Maggie E; Argueso, Cristiana T; Pajerowska-Mukhtar, Karolina M

    2016-07-11

    Cell death is a vital process for multicellular organisms. Programmed cell death (PCD) functions in a variety of processes including growth, development, and immune responses for homeostasis maintenance. In particular, plants and animals utilize PCD to control pathogen invasion and infected cell populations. Despite some similarity, there are a number of key differences between how these organisms initiate and regulate cell death. In contrast to animals, plants are sessile, lack a circulatory system, and have additional cellular structures, including cell walls and chloroplasts. Plant cells have the autonomous ability to induce localized cell death using conserved eukaryotic pathways as well as unique plant-specific pathways. Thus, in order to successfully infect host cells, pathogens must subvert immune responses and avoid detection to prevent PCD and allow infection. Here we discuss the roles of cell death in plant immune responses and the tactics pathogens utilize to avert cell death. PMID:27404256

  20. How cell death shapes cancer

    PubMed Central

    Labi, V; Erlacher, M

    2015-01-01

    Apoptosis has been established as a mechanism of anti-cancer defense. Members of the BCL-2 family are critical mediators of apoptotic cell death in health and disease, often found to be deregulated in cancer and believed to lead to the survival of malignant clones. However, over the years, a number of studies pointed out that a model in which cell death resistance unambiguously acts as a barrier against malignant disease might be too simple. This is based on paradoxical observations made in tumor patients as well as mouse models indicating that apoptosis can indeed drive tumor formation, at least under certain circumstances. One possible explanation for this phenomenon is that apoptosis can promote proliferation critically needed to compensate for cell loss, for example, upon therapy, and to restore tissue homeostasis. However, this, at the same time, can promote tumor development by allowing expansion of selected clones. Usually, tissue resident stem/progenitor cells are a major source for repopulation, some of them potentially carrying (age-, injury- or therapy-induced) genetic aberrations deleterious for the host. Thereby, apoptosis might drive genomic instability by facilitating the emergence of pathologic clones during phases of proliferation and subsequent replication stress-associated DNA damage. Tumorigenesis initiated by repeated cell attrition and repopulation, as confirmed in different genetic models, has parallels in human cancers, exemplified in therapy-induced secondary malignancies and myelodysplastic syndromes in patients with congenital bone marrow failure syndromes. Here, we aim to review evidence in support of the oncogenic role of stress-induced apoptosis. PMID:25741600

  1. Agonist-sensitive calcium pool in the pancreatic acinar cell. I. Permeability properties

    SciTech Connect

    Muallem, S.; Schoeffield, M.S.; Fimmel, C.J.; Pandol, S.J.

    1988-08-01

    45Ca2+ fluxes and free cytosolic Ca2+ (( Ca2+)i) were used to describe the Ca2+ permeability and Ca2+ reloading of the agonist-sensitive pool at rest, during stimulation, and at termination of stimulation. A sequence of stimulation with carbachol, inhibition with atropine (cycling), and restimulation with cholecystokinin octapeptide (CCK-8) was used to follow Ca2+ reloading. Reloading of the pool required extracellular Ca2+ and was measured as an increased rate and extent of 45Ca2+ uptake into the acini. The 45Ca2+ incorporated into cycled acini could be completely released with CCK-8. The dose-response curves for 45Ca uptake and release were identical to those of the hormonally evoked (Ca2+)i increase. The increased 45Ca2+ uptake during reloading was not due to an expansion of any intracellular pool size but reflects the labeling of the pool to isotopic equilibrium in cycled acini. The rate constant of Ca2+ efflux from the pool of resting cells was approximately 0.67 +/- 0.01/h. With stimulation, the Ca2+ permeability of the pool membrane rapidly increased, resulting in Ca2+ release into the cytosol and an increase in (Ca2+)i. With termination of stimulation, the Ca2+ permeability of the pool membrane rapidly decreased while the pool continued to reload with extracellular Ca2+. Labeling of the pool to isotopic equilibrium allowed determination of the amount of Ca2+ released from the pool, which was 2.94 +/- 0.06 nmol/mg protein. This indicates that total Ca2+ concentration in the pool is in the millimolar range.

  2. Dickkopf-3 regulates prostate epithelial cell acinar morphogenesis and prostate cancer cell invasion by limiting TGF-β-dependent activation of matrix metalloproteases.

    PubMed

    Romero, Diana; Al-Shareef, Zainab; Gorroño-Etxebarria, Irantzu; Atkins, Stephanie; Turrell, Frances; Chhetri, Jyoti; Bengoa-Vergniory, Nora; Zenzmaier, Christoph; Berger, Peter; Waxman, Jonathan; Kypta, Robert

    2016-01-01

    Dickkopf-3 (Dkk-3) is a secreted protein whose expression is downregulated in many types of cancer. Endogenous Dkk-3 is required for formation of acini in 3D cultures of prostate epithelial cells, where it inhibits transforming growth factor (TGF)-β/Smad signaling. Here, we examined the effects of Dkk-3 on the expression and activity of matrix metalloproteases (MMPs), which mediate the effects of TGF-β on extracellular matrix disassembly during tissue morphogenesis and promote invasion of tumor cells. Silencing of Dkk-3 in prostate epithelial cells resulted in increased expression and enzyme activity of MMP-2 and MMP-9. Inhibition of MMP-9 partially restored normal acinar morphogenesis in Dkk-3-silenced RWPE-1 prostate epithelial cells. In PC3 prostate cancer cells, Dkk-3 inhibited TGF-β-dependent migration and invasion. Inhibition was mediated by the Dkk-3 C-terminal cysteine-rich domain (Cys2), which also inhibited TGF-β-induced expression of MMP9 and MMP13. In contrast, Dkk-3, but not Cys2, increased formation of normal acini in Dkk-3-silenced prostate epithelial cells. These observations highlight a role for Dkk-3 in modulating TGF-β/MMP signals in the prostate, and suggest that the Dkk-3 Cys2 domain can be used as a basis for therapies that target the tumor promoting effects of TGF-β signaling in advanced prostate cancer.

  3. Cell death: a dynamic response concept.

    PubMed

    Loos, Benjamin; Engelbrecht, Anna-Mart

    2009-07-01

    Autophagy, apoptosis and necrosis have previously been described as distinct static processes that induce and execute cell death. Due to an increased use of novel techniques in mapping cellular death-techniques which allow for reporting of real-time data-the existence of "grey zones" between cell death modes and the existence of the "point of no return" within these have been revealed. This revelation demands the integration of new concepts in describing the cellular death process. Furthermore, since the contribution of autophagy in cell death or cell survival is still poorly understood, it is important to accurately describe its function within the dynamic framework of cell death. In this review cell death is viewed as a dynamic and integrative cellular response to ensure the highest likelihood of self-preservation. Suggestions are offered for conceptualizing cell death modes and their morphological features, both individually and in relation to one another. It addresses the need for distinguishing between dying cells and dead cells so as to better locate and control the onset of cell death. Most importantly, the fundamental role of autophagy, autophagic flux, and the effects of the intracellular metabolic environment on the kinetics of the cell death modes are stressed. It also contextualizes the kinetic dimension of cell death as a process and aims to contribute towards a better understanding of autophagy as a key mechanism within this process. Understanding the dynamic nature of the cell death process and autophagy's central role can reveal new insight for therapeutic intervention in preventing cell death.

  4. Molecular definitions of cell death subroutines: recommendations of the Nomenclature Committee on Cell Death 2012

    PubMed Central

    Galluzzi, L; Vitale, I; Abrams, J M; Alnemri, E S; Baehrecke, E H; Blagosklonny, M V; Dawson, T M; Dawson, V L; El-Deiry, W S; Fulda, S; Gottlieb, E; Green, D R; Hengartner, M O; Kepp, O; Knight, R A; Kumar, S; Lipton, S A; Lu, X; Madeo, F; Malorni, W; Mehlen, P; Nuñez, G; Peter, M E; Piacentini, M; Rubinsztein, D C; Shi, Y; Simon, H-U; Vandenabeele, P; White, E; Yuan, J; Zhivotovsky, B; Melino, G; Kroemer, G

    2012-01-01

    In 2009, the Nomenclature Committee on Cell Death (NCCD) proposed a set of recommendations for the definition of distinct cell death morphologies and for the appropriate use of cell death-related terminology, including ‘apoptosis', ‘necrosis' and ‘mitotic catastrophe'. In view of the substantial progress in the biochemical and genetic exploration of cell death, time has come to switch from morphological to molecular definitions of cell death modalities. Here we propose a functional classification of cell death subroutines that applies to both in vitro and in vivo settings and includes extrinsic apoptosis, caspase-dependent or -independent intrinsic apoptosis, regulated necrosis, autophagic cell death and mitotic catastrophe. Moreover, we discuss the utility of expressions indicating additional cell death modalities. On the basis of the new, revised NCCD classification, cell death subroutines are defined by a series of precise, measurable biochemical features. PMID:21760595

  5. Programmed Cell Death During Caenorhabditis elegans Development.

    PubMed

    Conradt, Barbara; Wu, Yi-Chun; Xue, Ding

    2016-08-01

    Programmed cell death is an integral component of Caenorhabditis elegans development. Genetic and reverse genetic studies in C. elegans have led to the identification of many genes and conserved cell death pathways that are important for the specification of which cells should live or die, the activation of the suicide program, and the dismantling and removal of dying cells. Molecular, cell biological, and biochemical studies have revealed the underlying mechanisms that control these three phases of programmed cell death. In particular, the interplay of transcriptional regulatory cascades and networks involving multiple transcriptional regulators is crucial in activating the expression of the key death-inducing gene egl-1 and, in some cases, the ced-3 gene in cells destined to die. A protein interaction cascade involving EGL-1, CED-9, CED-4, and CED-3 results in the activation of the key cell death protease CED-3, which is tightly controlled by multiple positive and negative regulators. The activation of the CED-3 caspase then initiates the cell disassembly process by cleaving and activating or inactivating crucial CED-3 substrates; leading to activation of multiple cell death execution events, including nuclear DNA fragmentation, mitochondrial elimination, phosphatidylserine externalization, inactivation of survival signals, and clearance of apoptotic cells. Further studies of programmed cell death in C. elegans will continue to advance our understanding of how programmed cell death is regulated, activated, and executed in general. PMID:27516615

  6. Cell biology. Metabolic control of cell death.

    PubMed

    Green, Douglas R; Galluzzi, Lorenzo; Kroemer, Guido

    2014-09-19

    Beyond their contribution to basic metabolism, the major cellular organelles, in particular mitochondria, can determine whether cells respond to stress in an adaptive or suicidal manner. Thus, mitochondria can continuously adapt their shape to changing bioenergetic demands as they are subjected to quality control by autophagy, or they can undergo a lethal permeabilization process that initiates apoptosis. Along similar lines, multiple proteins involved in metabolic circuitries, including oxidative phosphorylation and transport of metabolites across membranes, may participate in the regulated or catastrophic dismantling of organelles. Many factors that were initially characterized as cell death regulators are now known to physically or functionally interact with metabolic enzymes. Thus, several metabolic cues regulate the propensity of cells to activate self-destructive programs, in part by acting on nutrient sensors. This suggests the existence of "metabolic checkpoints" that dictate cell fate in response to metabolic fluctuations. Here, we discuss recent insights into the intersection between metabolism and cell death regulation that have major implications for the comprehension and manipulation of unwarranted cell loss.

  7. Transdifferentiation of mouse adipose-derived stromal cells into acinar cells of the submandibular gland using a co-culture system.

    PubMed

    Lee, Jingu; Park, Sangkyu; Roh, Sangho

    2015-05-15

    A loss of salivary gland function often occurs after radiation therapy in head and neck tumors, though secretion of saliva by the salivary glands is essential for the health and maintenance of the oral environment. Transplantation of salivary acinar cells (ACs), in part, may overcome the side effects of therapy. Here we directly differentiated mouse adipose-derived stromal cells (ADSCs) into ACs using a co-culture system. Multipotent ADSCs can be easily collected from stromal vascular fractions of adipose tissues. The isolated ADSCs showed positive expression of markers such as integrin beta-1 (CD29), cell surface glycoprotein (CD44), endoglin (CD105), and Nanog. The cells were able to differentiate into adipocytes, osteoblasts, and neural-like cells after 14 days in culture. ADSCs at passage 2 were co-cultured with mouse ACs in AC culture medium using the double-chamber (co-culture system) to avoid mixing the cell types. The ADSCs in this co-culture system expressed markers of ACs, such as α-amylases and aquaporin5, in both mRNA and protein. ADSCs cultured in AC-conditioned medium also expressed AC markers. Cellular proliferation and senescence analyses demonstrated that cells in the co-culture group showed lower senescence and a higher proliferation rate than the AC-conditioned medium group at Days 14 and 21. The results above imply direct conversion of ADSCs into ACs under the co-culture system; therefore, ADSCs may be a stem cell source for the therapy for salivary gland damage.

  8. Chemotherapeutic Approaches for Targeting Cell Death Pathways

    PubMed Central

    Ricci, M. Stacey; Zong, Wei-Xing

    2011-01-01

    For several decades, apoptosis has taken center stage as the principal mechanism of programmed cell death in mammalian tissues. It also has been increasingly noted that conventional chemotherapeutic agents not only elicit apoptosis but other forms of nonapoptotic death such as necrosis, autophagy, mitotic catastrophe, and senescence. This review presents background on the signaling pathways involved in the different cell death outcomes. A re-examination of what we know about chemotherapy-induced death is vitally important in light of new understanding of nonapoptotic cell death signaling pathways. If we can precisely activate or inhibit molecules that mediate the diversity of cell death outcomes, perhaps we can succeed in more effective and less toxic chemotherapeutic regimens. PMID:16614230

  9. Spontaneous cell death in the chorion laeve.

    PubMed

    Parmley, T H

    1990-06-01

    The granulosa cells of the dominant follicle grow, differentiate, and die in a roughly predictable amount of time. Because the simultaneous death of this population of cells results in menstruation, one may say that the life span of this population of cells "times" the menstrual cycle. Metamorphosis in amphibians and morphogenesis in several vertebrates are other examples of developmental milestones that are "timed" by the life span of specific cell populations. In all these examples, cell death is associated with a specific histology, apoptosis. Apoptosis characterizes the cell death that produces the progressive disappearance of the trophoblast in the chorion laeve as term is approached. Therefore, the histology of trophoblastic death in the near-term chorion laeve corresponds to that of populations of cells with life spans that "time" developmental events. The trophoblastic cell population of the chorion laeve is prematurely destroyed by infiltrating maternal leukocytes in cases of chorioamnionitis.

  10. Constitutive nitric oxide synthase-mediated caspase-3 S-nitrosylation in ghrelin protection against Porphyromonas gingivalis-induced salivary gland acinar cell apoptosis.

    PubMed

    Slomiany, B L; Slomiany, A

    2010-06-01

    Recent advances in identifying the salivary constituents capable of influencing the oral mucosal inflammatory responses have brought to focus the importance of a peptide hormone, ghrelin. Here, we report on the involvement of ghrelin in controlling the apoptotic processes induced in sublingual salivary gland acinar cells by the lipopolysaccharide (LPS) of a periodontopathic bacterium, Porphyromonas gingivalis. We show that the countering effect of ghrelin on the LPS-induced acinar cell apoptosis was associated with the increase in constitutive nitric oxide synthase (cNOS) activity, and the reduction in caspase-3 and inducible nitric oxide synthase (iNOS). The loss in countering effect of ghrelin on the LPS-induced changes in apoptosis and caspase-3 activity was attained with Src kinase inhibitor, PP2, as well as Akt inhibitor, SH-5, and cNOS inhibitor, L-NAME, but not the iNOS inhibitor, 1400W. The effect of ghrelin on the LPS-induced changes in cNOS activity, moreover, was reflected in the increased cNOS phosphorylation that was sensitive to PP2 as well as SH-5. Furthermore, the ghrelin-induced up-regulation in cNOS activity was associated with the increase in caspase-3 S-nitrosylation that was susceptible to the blockage by SH-5 and L-NAME. The findings point to the involvement of ghrelin in Src/Akt kinase-mediated cNOS activation and the apoptogenic signal inhibition through the NO-induced caspase-3 S-nitrosylation.

  11. Role of epidermal growth factor receptor transactivation in the activation of cytosolic phospholipase A(2) in leptin protection of salivary gland acinar cells against ethanol cytotoxicity.

    PubMed

    Slomiany, B L; Slomiany, A

    2009-06-01

    A pleiotropic hormone, leptin, secreted into saliva by the acinar cells of salivary glands is an important mediator of the processes of oral mucosal defense. Here, we report on the role of epidermal growth factor receptor (EGFR) transactivation in the signaling events that mediate leptin protection of sublingual salivary gland acinar cells against ethanol cytotoxicity. We show that the protective effect of leptin against ethanol cytotoxicity was associated with the increased EGFR protein tyrosine kinase and cytosolic phospholipase A(2) (cPLA(2)) activity, and characterized by a marked increase in matrix metalloproteinase MMP-9 and arachidonic acid (AA) release, and PGE(2) generation. The loss in countering capacity of leptin against ethanol cytotoxicity was attained with JAK inhibitor AG490, Src inhibitor PP2, and EGFR inhibitor AG1478, as well as ERK inhibitor PD98059. Moreover, the agents evoked also the inhibition in leptin-induced up-regulation in cPLA(2) activity, AA release, and PGE(2) generation. The changes caused by leptin in EGFR phosphorylation, MMP-9, and cPLA(2) activation were susceptible to suppression by metalloprotease inhibitor GM6001, but the production of MMP-9 was not affected by EGFR inhibitor AG1478 or PKC inhibitor Ro318220. These findings point to the involvement of MMP-9 in the event of leptin-induced EGFR transactivation that results in the signaling cascade leading to cPLA(2) activation and up-regulation in PGE(2) generation, thus providing new insights into the mechanism of oral mucosal protection against ethanol toxicity.

  12. Joint aging and chondrocyte cell death

    PubMed Central

    Grogan, Shawn P; D’Lima, Darryl D

    2010-01-01

    Articular cartilage extracellular matrix and cell function change with age and are considered to be the most important factors in the development and progression of osteoarthritis. The multifaceted nature of joint disease indicates that the contribution of cell death can be an important factor at early and late stages of osteoarthritis. Therefore, the pharmacologic inhibition of cell death is likely to be clinically valuable at any stage of the disease. In this article, we will discuss the close association between diverse changes in cartilage aging, how altered conditions influence chondrocyte death, and the implications of preventing cell loss to retard osteoarthritis progression and preserve tissue homeostasis. PMID:20671988

  13. Melatonin induces the expression of Nrf2-regulated antioxidant enzymes via PKC and Ca2+ influx activation in mouse pancreatic acinar cells.

    PubMed

    Santofimia-Castaño, Patricia; Clea Ruy, Deborah; Garcia-Sanchez, Lourdes; Jimenez-Blasco, Daniel; Fernandez-Bermejo, Miguel; Bolaños, Juan P; Salido, Gines M; Gonzalez, Antonio

    2015-10-01

    The goal of this study was to evaluate the potential activation of the nuclear factor erythroid 2-related factor and the antioxidant-responsive element (Nrf2-ARE) signaling pathway in response to melatonin in isolated mouse pancreatic acinar cells. Changes in intracellular free Ca(2+) concentration were followed by fluorimetric analysis of fura-2-loaded cells. The activations of PKC and JNK were measured by Western blot analysis. Quantitative reverse transcription-polymerase chain reaction was employed to detect the expression of Nrf2-regulated antioxidant enzymes. Immunocytochemistry was employed to determine nuclear location of phosphorylated Nrf2, and the cellular redox state was monitored following MitoSOX Red-derived fluorescence. Our results show that stimulation of fura-2-loaded cells with melatonin (1 µM to 1 mM), in the presence of Ca(2+) in the extracellular medium, induced a slow and progressive increase of [Ca(2+)](c) toward a stable level. Melatonin did not inhibit the typical Ca(2+) response induced by CCK-8 (1 nM). When the cells were challenged with indoleamine in the absence of Ca(2+) in the extracellular solution (medium containing 0.5 mM EGTA) or in the presence of 1 mM LaCl(3), to inhibit Ca(2+) entry, we could not detect any change in [Ca(2+)](c). Nevertheless, CCK-8 (1 nM) was able to induce the typical mobilization of Ca(2+). When the cells were incubated with the PKC activator PMA (1 µM) in the presence of Ca(2+) in the extracellular medium, we observed a response similar to that noted when the cells were challenged with melatonin 100 µM. However, in the presence of Ro31-8220 (3 µM), a PKC inhibitor, stimulation of cells with melatonin failed to evoke changes in [Ca(2+)]c. Immunoblots, using an antibody specific for phospho-PKC, revealed that melatonin induces PKCα activation, either in the presence or in the absence of external Ca(2+). Melatonin induced the phosphorylation and nuclear translocation of the transcription factor Nrf2, and

  14. Autophagy and cell death in model organisms.

    PubMed

    Kourtis, N; Tavernarakis, N

    2009-01-01

    Autophagy evolved in unicellular eukaryotes as a means for surviving nutrient stress. During the course of evolution, as multicellular organisms developed specialized cell types and complex intracellular signalling networks, autophagy has been summoned to serve additional cellular functions. Numerous recent studies indicate that apart from its pro-survival role under nutrient limitation, autophagy also participates in cell death. However, the precise role of this catabolic process in dying cells is not fully understood. Although in certain situations autophagy has a protective function, in other types of cell death it actually contributes to cellular destruction. Simple model organisms ranging from the unicellular Saccharomyces cerevisiae to the soil amoeba Dictyostelium discoideum and the metazoans Caenorhabditis elegans and Drosophila melanogaster provide clearly defined cell death paradigms that can be used to dissect the involvement of autophagy in cell death, at the molecular level. In this review, we survey current research in simple organisms, linking autophagy to cell death and discuss the complex interplay between autophagy, cell survival and cell death. PMID:19079286

  15. Entosis and Related Forms of Cell Death within Cells.

    PubMed

    Wang, Y; Wang, X-D

    2015-01-01

    By eliminating the unneeded or mutant cells, programmed cell death actively participates in a wide range of biological processes from embryonic development to homeostasis maintenance in adult. Continuing efforts have identified multiple cell death pathways, with apoptosis, necrosis and autophage the mostly studied. Recently a unique cell death pathway called "cell-in-cell death" has been defined. Unlike traditional cell death pathways, cell-in-cell death, characterized by cell death within another cell, is triggered by the invasion of one cell into its neighbor and executed by either lysosome-dependent degradation or caspase-dependent apoptosis. With remarkable progresses on cell-in-cell over past few years, multiple mechanisms, including entosis, cannibalism and emperitosis, are found to be responsible for cell-in-cell death. Some key questions, such as specific biochemical markers to distinguish precisely the properties of different cell-in-cell structures and the physiological and pathological relevance, remain to be addressed. In light of this situation and a surge of interests, leading scientists in this field intend to share with readers current research progresses on cell-in-cell structures from different model systems through this special edition on cell-in-cell. The mechanistic advances will be highlighted while the future researches be speculated. PMID:26511710

  16. Morphological classification of plant cell deaths

    PubMed Central

    van Doorn, W G; Beers, E P; Dangl, J L; Franklin-Tong, V E; Gallois, P; Hara-Nishimura, I; Jones, A M; Kawai-Yamada, M; Lam, E; Mundy, J; Mur, L A J; Petersen, M; Smertenko, A; Taliansky, M; Van Breusegem, F; Wolpert, T; Woltering, E; Zhivotovsky, B; Bozhkov, P V

    2011-01-01

    Programmed cell death (PCD) is an integral part of plant development and of responses to abiotic stress or pathogens. Although the morphology of plant PCD is, in some cases, well characterised and molecular mechanisms controlling plant PCD are beginning to emerge, there is still confusion about the classification of PCD in plants. Here we suggest a classification based on morphological criteria. According to this classification, the use of the term ‘apoptosis' is not justified in plants, but at least two classes of PCD can be distinguished: vacuolar cell death and necrosis. During vacuolar cell death, the cell contents are removed by a combination of autophagy-like process and release of hydrolases from collapsed lytic vacuoles. Necrosis is characterised by early rupture of the plasma membrane, shrinkage of the protoplast and absence of vacuolar cell death features. Vacuolar cell death is common during tissue and organ formation and elimination, whereas necrosis is typically found under abiotic stress. Some examples of plant PCD cannot be ascribed to either major class and are therefore classified as separate modalities. These are PCD associated with the hypersensitive response to biotrophic pathogens, which can express features of both necrosis and vacuolar cell death, PCD in starchy cereal endosperm and during self-incompatibility. The present classification is not static, but will be subject to further revision, especially when specific biochemical pathways are better defined. PMID:21494263

  17. Regulated cell death and adaptive stress responses.

    PubMed

    Galluzzi, Lorenzo; Bravo-San Pedro, José Manuel; Kepp, Oliver; Kroemer, Guido

    2016-06-01

    Eukaryotic cells react to potentially dangerous perturbations of the intracellular or extracellular microenvironment by activating rapid (transcription-independent) mechanisms that attempt to restore homeostasis. If such perturbations persist, cells may still try to cope with stress by activating delayed and robust (transcription-dependent) adaptive systems, or they may actively engage in cellular suicide. This regulated form of cell death can manifest with various morphological, biochemical and immunological correlates, and constitutes an ultimate attempt of stressed cells to maintain organismal homeostasis. Here, we dissect the general organization of adaptive cellular responses to stress, their intimate connection with regulated cell death, and how the latter operates for the preservation of organismal homeostasis.

  18. Programmed cell death in cereal aleurone.

    PubMed

    Fath, A; Bethke, P; Lonsdale, J; Meza-Romero, R; Jones, R

    2000-10-01

    Progress in understanding programmed cell death (PCD) in the cereal aleurone is described. Cereal aleurone cells are specialized endosperm cells that function to synthesize and secrete hydrolytic enzymes that break down reserves in the starchy endosperm. Unlike the cells of the starchy endosperm, aleurone cells are viable in mature grain but undergo PCD when germination is triggered or when isolated aleurone layers or protoplasts are incubated in gibberellic acid (GA). Abscisic acid (ABA) slows down the process of aleurone cell death and isolated aleurone protoplasts can be kept alive in media containing ABA for up to 6 months. Cell death in barley aleurone occurs only after cells become highly vacuolated and is manifested in an abrupt loss of plasma membrane integrity. Aleurone cell death does not follow the apoptotic pathway found in many animal cells. The hallmarks of apoptosis, including internucleosomal DNA cleavage, plasma membrane and nuclear blebbing and formation of apoptotic bodies, are not observed in dying aleurone cells. PCD in barley aleurone cells is accompanied by the accumulation of a spectrum of nuclease and protease activities and the loss of organelles as a result of cellular autolysis.

  19. Serotonin promotes acinar dedifferentiation following pancreatitis-induced regeneration in the adult pancreas.

    PubMed

    Saponara, Enrica; Grabliauskaite, Kamile; Bombardo, Marta; Buzzi, Raphael; Silva, Alberto B; Malagola, Ermanno; Tian, Yinghua; Hehl, Adrian B; Schraner, Elisabeth M; Seleznik, Gitta M; Zabel, Anja; Reding, Theresia; Sonda, Sabrina; Graf, Rolf

    2015-12-01

    The exocrine pancreas exhibits a distinctive capacity for tissue regeneration and renewal following injury. This regenerative ability has important implications for a variety of disorders, including pancreatitis and pancreatic cancer, diseases associated with high morbidity and mortality. Thus, understanding its underlying mechanisms may help in developing therapeutic interventions. Serotonin has been recognized as a potent mitogen for a variety of cells and tissues. Here we investigated whether serotonin exerts a mitogenic effect in pancreatic acinar cells in three regenerative models, inflammatory tissue injury following pancreatitis, tissue loss following partial pancreatectomy, and thyroid hormone-stimulated acinar proliferation. Genetic and pharmacological techniques were used to modulate serotonin levels in vivo. Acinar dedifferentiation and cell cycle progression during the regenerative phase were investigated over the course of 2 weeks. By comparing acinar proliferation in the different murine models of regeneration, we found that serotonin did not affect the clonal regeneration of mature acinar cells. Serotonin was, however, required for acinar dedifferentiation following inflammation-mediated tissue injury. Specifically, lack of serotonin resulted in delayed up-regulation of progenitor genes and delayed the formation of acinar-to-ductal metaplasia and defective acinar cell proliferation. We identified serotonin-dependent acinar secretion as a key step in progenitor-based regeneration, as it promoted acinar cell dedifferentiation and the recruitment of type 2 macrophages. Finally, we identified a regulatory Hes1-Ptfa axis in the uninjured adult pancreas, activated by zymogen secretion. Our findings indicated that serotonin plays a critical role in the regeneration of the adult pancreas following pancreatitis by promoting the dedifferentiation of acinar cells.

  20. Serotonin promotes acinar dedifferentiation following pancreatitis-induced regeneration in the adult pancreas.

    PubMed

    Saponara, Enrica; Grabliauskaite, Kamile; Bombardo, Marta; Buzzi, Raphael; Silva, Alberto B; Malagola, Ermanno; Tian, Yinghua; Hehl, Adrian B; Schraner, Elisabeth M; Seleznik, Gitta M; Zabel, Anja; Reding, Theresia; Sonda, Sabrina; Graf, Rolf

    2015-12-01

    The exocrine pancreas exhibits a distinctive capacity for tissue regeneration and renewal following injury. This regenerative ability has important implications for a variety of disorders, including pancreatitis and pancreatic cancer, diseases associated with high morbidity and mortality. Thus, understanding its underlying mechanisms may help in developing therapeutic interventions. Serotonin has been recognized as a potent mitogen for a variety of cells and tissues. Here we investigated whether serotonin exerts a mitogenic effect in pancreatic acinar cells in three regenerative models, inflammatory tissue injury following pancreatitis, tissue loss following partial pancreatectomy, and thyroid hormone-stimulated acinar proliferation. Genetic and pharmacological techniques were used to modulate serotonin levels in vivo. Acinar dedifferentiation and cell cycle progression during the regenerative phase were investigated over the course of 2 weeks. By comparing acinar proliferation in the different murine models of regeneration, we found that serotonin did not affect the clonal regeneration of mature acinar cells. Serotonin was, however, required for acinar dedifferentiation following inflammation-mediated tissue injury. Specifically, lack of serotonin resulted in delayed up-regulation of progenitor genes and delayed the formation of acinar-to-ductal metaplasia and defective acinar cell proliferation. We identified serotonin-dependent acinar secretion as a key step in progenitor-based regeneration, as it promoted acinar cell dedifferentiation and the recruitment of type 2 macrophages. Finally, we identified a regulatory Hes1-Ptfa axis in the uninjured adult pancreas, activated by zymogen secretion. Our findings indicated that serotonin plays a critical role in the regeneration of the adult pancreas following pancreatitis by promoting the dedifferentiation of acinar cells. PMID:26235267

  1. Pancreatic Acinar Cells Employ miRNAs as Mediators of Intercellular Communication to Participate in the Regulation of Pancreatitis-Associated Macrophage Activation

    PubMed Central

    Zhao, Yong; Wang, Hao; Qiao, Xin; Sun, Bei

    2016-01-01

    Macrophage activation plays an important role in the inflammatory response in acute pancreatitis. In the present study, the activation of AR42J pancreatic acinar cells was induced by taurolithocholate treatment. The results showed that the culture medium from the activated AR42J cells significantly enhanced NFκB activation in the macrophages compared to that without taurolithocholate treatment. Additionally, the precipitates obtained from ultracentrifugation of the culture media that were rich in exosomes were markedly more potent in activating macrophages compared with the supernatant fraction lacking exosomes. The results indicated that the mediators carried by the exosomes played important roles in macrophage activation. Exosomal miRNAs were extracted and examined using microarrays. A total of 115 differentially expressed miRNAs were identified, and 30 showed upregulated expression, while 85 displayed downregulated expression. Target genes of the differentially expressed miRNAs were predicted using TargetScan, MiRanda, and PicTar software programs. The putative target genes were subjected to KEGG functional analysis. The functions of the target genes were primarily enriched in MAPK pathways. Specifically, the target genes regulated macrophage activation through the TRAF6-TAB2-TAK1-NIK/IKK-NFκB pathway. As the mediators of signal transduction, miRNAs and their predicted target mRNAs regulate every step in the MAPK pathway. PMID:27546996

  2. Pancreatic Acinar Cells Employ miRNAs as Mediators of Intercellular Communication to Participate in the Regulation of Pancreatitis-Associated Macrophage Activation.

    PubMed

    Zhao, Yong; Wang, Hao; Lu, Ming; Qiao, Xin; Sun, Bei; Zhang, Weihui; Xue, Dongbo

    2016-01-01

    Macrophage activation plays an important role in the inflammatory response in acute pancreatitis. In the present study, the activation of AR42J pancreatic acinar cells was induced by taurolithocholate treatment. The results showed that the culture medium from the activated AR42J cells significantly enhanced NFκB activation in the macrophages compared to that without taurolithocholate treatment. Additionally, the precipitates obtained from ultracentrifugation of the culture media that were rich in exosomes were markedly more potent in activating macrophages compared with the supernatant fraction lacking exosomes. The results indicated that the mediators carried by the exosomes played important roles in macrophage activation. Exosomal miRNAs were extracted and examined using microarrays. A total of 115 differentially expressed miRNAs were identified, and 30 showed upregulated expression, while 85 displayed downregulated expression. Target genes of the differentially expressed miRNAs were predicted using TargetScan, MiRanda, and PicTar software programs. The putative target genes were subjected to KEGG functional analysis. The functions of the target genes were primarily enriched in MAPK pathways. Specifically, the target genes regulated macrophage activation through the TRAF6-TAB2-TAK1-NIK/IKK-NFκB pathway. As the mediators of signal transduction, miRNAs and their predicted target mRNAs regulate every step in the MAPK pathway. PMID:27546996

  3. Nineteenth century research on cell death.

    PubMed

    Clarke, P G H; Clarke, S

    2012-10-01

    This paper reviews research on cell death in the 19th C. The first report of cell death was by Vogt in 1842, which was remarkably soon after the establishment of the cell theory by Schleiden and Schwann between 1838 and 1842. Initial studies on cell death, including that of Vogt, focused on its occurrence in metamorphosis (Vogt, 1842; Prévost and Lebert, 1844; Weismann, 1863-1866) or in blatant pathology (Virchow, 1858), but as histological techniques improved it was found to be involved in more subtle roles in numerous situations including endochondral ossification (Stieda, 1872), ovarian follicle atresia (Flemming, 1885), cell turnover (Nissen, 1886), the wholesale loss of a population of sensory neurons in fish (Beard, 1889), and the naturally occurring histogenetic death of myocytes (Felix, 1889) and neurons (Collin, 1906). The current categorization of cell death into about three main morphological types has 19th century roots in that apoptosis was well described by Flemming (1885), who called it chromatolysis, and various authors including Noetzel (1895) proposed a threefold classification. This article is part of a Special Issue entitled "Apoptosis: Four Decades Later". PMID:23069997

  4. Programmed cell death and hybrid incompatibility.

    PubMed

    Frank, S A; Barr, C M

    2003-01-01

    We propose a new theory to explain developmental aberrations in plant hybrids. In our theory, hybrid incompatibilities arise from imbalances in the mechanisms that cause male sterility in hermaphroditic plants. Mitochondria often cause male sterility by killing the tapetal tissue that nurtures pollen mother cells. Recent evidence suggests that mitochondria destroy the tapetum by triggering standard pathways of programmed cell death. Some nuclear genotypes repress mitochondrial male sterility and restore pollen fertility. Normal regulation of tapetal development therefore arises from a delicate balance between the disruptive effects of mitochondria and the defensive countermeasures of the nuclear genes. In hybrids, incompatibilities between male-sterile mitochondria and nuclear restorers may frequently upset the regulatory control of programmed cell death, causing tapetal abnormalities and male sterility. We propose that hybrid misregulation of programmed cell death may also spill over into other tissues, explaining various developmental aberrations observed in hybrids.

  5. Parvovirus infection-induced cell death and cell cycle arrest

    PubMed Central

    Chen, Aaron Yun; Qiu, Jianming

    2011-01-01

    The cytopathic effects induced during parvovirus infection have been widely documented. Parvovirus infection-induced cell death is often directly associated with disease outcomes (e.g., anemia resulting from loss of erythroid progenitors during parvovirus B19 infection). Apoptosis is the major form of cell death induced by parvovirus infection. However, nonapoptotic cell death, namely necrosis, has also been reported during infection of the minute virus of mice, parvovirus H-1 and bovine parvovirus. Recent studies have revealed multiple mechanisms underlying the cell death during parvovirus infection. These mechanisms vary in different parvoviruses, although the large nonstructural protein (NS)1 and the small NS proteins (e.g., the 11 kDa of parvovirus B19), as well as replication of the viral genome, are responsible for causing infection-induced cell death. Cell cycle arrest is also common, and contributes to the cytopathic effects induced during parvovirus infection. While viral NS proteins have been indicated to induce cell cycle arrest, increasing evidence suggests that a cellular DNA damage response triggered by an invading single-stranded parvoviral genome is the major inducer of cell cycle arrest in parvovirus-infected cells. Apparently, in response to infection, cell death and cell cycle arrest of parvovirus-infected cells are beneficial to the viral cell lifecycle (e.g., viral DNA replication and virus egress). In this article, we will discuss recent advances in the understanding of the mechanisms underlying parvovirus infection-induced cell death and cell cycle arrest. PMID:21331319

  6. HCO3- Transport through Anoctamin/Transmembrane Protein ANO1/TMEM16A in Pancreatic Acinar Cells Regulates Luminal pH.

    PubMed

    Han, Yanfeng; Shewan, Annette M; Thorn, Peter

    2016-09-23

    The identification of ANO1/TMEM16A as the likely calcium-dependent chloride channel of exocrine glands has led to a more detailed understanding of its biophysical properties. This includes a calcium-dependent change in channel selectivity and evidence that HCO3 (-) permeability can be significant. Here we use freshly isolated pancreatic acini that preserve the luminal structure to measure intraluminal pH and test the idea that ANO1/TMEM16A contributes to luminal pH balance. Our data show that, under physiologically relevant stimulation with 10 pm cholesystokinin, the luminal acid load that results from the exocytic fusion of zymogen granules is significantly blunted by HCO3 (-) buffer in comparison with HEPES, and that this is blocked by the specific TMEM16A inhibitor T16inh-A01. Furthermore, in a model of acute pancreatitis, we observed substantive luminal acidification and provide evidence that ANO1/TMEM16A acts to attenuate this pH shift. We conclude that ANO1/TMEM16A is a significant pathway in pancreatic acinar cells for HCO3 (-) secretion into the lumen.

  7. Insulin withdrawal-induced cell death in adult hippocampal neural stem cells as a model of autophagic cell death.

    PubMed

    Baek, Seung-Hoon; Kim, Eun-Kyoung; Goudreau, John L; Lookingland, Keith J; Kim, Seong Who; Yu, Seong-Woon

    2009-02-01

    The term "autophagic cell death" was coined to describe a form of cell death associated with the massive formation of autophagic vacuoles without signs of apoptosis. However, questions about the actual role of autophagy and its molecular basis in cell death remain to be elucidated. We recently reported that adult hippocampal neural stem (HCN) cells undergo autophagic cell death following insulin withdrawal. Insulin-deprived HCN cells exhibit morphological and biochemical markers of autophagy, including accumulation of Beclin 1 and the type II form of microtubule-associated protein 1 light chain 3 (LC3) without evidence of apoptosis. Suppression of autophagy by knockdown of Atg7 reduces cell death, whereas promotion of autophagy with rapamycin augments cell death in insulin-deficient HCN cells. These data reveal a causative role of autophagy in insulin withdrawal-induced HCN cell death. HCN cells have intact apoptotic capability despite the lack of apoptosis following insulin withdrawal. Our study demonstrates that autophagy is the default cell death mechanism in insulin-deficient HCN cells, and provides a genuine model of autophagic cell death in apoptosis-intact cells. Novel insight into molecular mechanisms of this underappreciated form of programmed cell death should facilitate the development of therapeutic methods to cope with human diseases caused by dysregulated cell death.

  8. Time-Lapse Imaging of Cell Death.

    PubMed

    Wallberg, Fredrik; Tenev, Tencho; Meier, Pascal

    2016-03-01

    The best approach to distinguish between necrosis and apoptosis is time-lapse video microscopy. This technique enables a biological process to be photographed at regular intervals over a period, which may last from a few hours to several days, and can be applied to cells in culture or in vivo. We have established two time-lapse microscopy methods based on different ways of calculating cell death: semiautomated and automated. In the semiautomated approach, cell death can be visualized by staining with combinations of Alexa Fluor 647-conjugated Annexin V and Sytox Green (SG), or Annexin V(FITC) and Propidium iodide (PI). The automated method is similar except that all cells are labeled with dyes. This allows faster quantification of data. To this end Cell Tracker Green is used to label all cells at time zero in combination with PI and Alexa Fluor 647-conjugated Annexin V. Necrotic cell death is accompanied by either simultaneous labeling with Annexin V and PI or SG (double-positive), or direct PI or SG staining. Additionally, necrotic cells display characteristic morphology, such as cytoplasmic swelling. In contrast to necrosis where membrane permeabilization is an early event, cells that die by apoptosis lose their membrane permeability relatively late. Therefore, the time between Annexin V staining and PI or SG uptake (double-positive) can be used to distinguish necrosis from apoptosis. This protocol describes the analysis of cell death by time-lapse imaging of HT1080 and L929 cells stained with these dyes, but it can be readily adapted to other cell types of interest. PMID:26933245

  9. The apoptosome: signalling platform of cell death.

    PubMed

    Riedl, Stefan J; Salvesen, Guy S

    2007-05-01

    Recent work on the initial switches that trigger cell death has revealed surprising inventions of nature that ensure the ordered suicide of a cell that has been selected for demise. Particularly intriguing is how a signal--the release of cytochrome c from the mitochondria--is translated into the activation of the death cascade, which leads to a point of no return. Now there is new understanding of how this crucial process is delicately handled by a cytosolic signalling platform known as the apoptosome. The formation of the apoptosome and the activation of its effector, caspase-9, reveals a sophisticated mechanism that might be more common than was initially thought. PMID:17377525

  10. The deaths of a cell: how language and metaphor influence the science of cell death.

    PubMed

    Reynolds, Andrew S

    2014-12-01

    Multicellular development and tissue maintenance involve the regular elimination of damaged and healthy cells. The science of this genetically regulated cell death is particularly rich in metaphors: 'programmed cell death' or 'cell suicide' is considered an 'altruistic' act on the part of a cell for the benefit of the organism as a whole. It is also considered a form of 'social control' exerted by the body/organism over its component cells. This paper analyzes the various functions of these metaphors and critical discussion about them within the scientific community. Bodies such as the Nomenclature Committee on Cell Death (NCCD) have been charged with bringing order to the language of cell death to facilitate scientific progress. While the NCCD recommends adopting more objective biochemical terminology to describe the mechanisms of cell death, the metaphors in question retain an important function by highlighting the broader context within which cell death occurs. Scientific metaphors act as conceptual 'tools' which fulfill various roles, from highlighting a phenomenon as of particular interest, situating it in a particular context, or suggesting explanatory causal mechanisms.

  11. Cell death pathways associated with PDT

    NASA Astrophysics Data System (ADS)

    Kessel, David; Reiners, John J., Jr.

    2006-02-01

    Photodynamic therapy leads to both direct and indirect tumor cell death. The latter also involves the consequences of vascular shut-down and immunologic effects. While these factors are a major factor in tumor eradication, there is usually an element of direct cell killing that can reduce the cell population by as much as 2-3 logs. Necrosis was initially believed to represent the predominant PDT death mechanism. An apoptotic response to PDT was first reported by Oleinick in 1991, using a sensitizer that targets the anti-apoptotic protein Bcl-2. Apoptosis leads to fragmentation of DNA and of cells into apoptotic bodies that are removed by phagocytosis. Inflammatory effects are minimized, and the auto- catalytic elements of the process can amplify the death signal. In this study, we examined consequences of Bcl-2 photodamage by a porphycene sensitizer that targets the ER and causes photodamage to the anti-apoptotic protein Bcl-2. Death patterns after Bcl-2 inactivation by a small-molecular antagonist were also assessed. In addition to apoptosis, we also characterized a hitherto undescribed PDT effect, the initiation of autophagy. Autophagy was initially identified as a cell survival pathway, allowing the recycling of components as nutrients become scarce. We propose that autophagy can also represent both a potential survival pathway after PDT damage to cellular organelles, as well as a cell-death pathway. Recent literature reports indicate that autophagy, as well as apoptosis, can be evoked after down-regulation of Bcl-2, a result consistent with results reported here.

  12. Programmed cell death in seeds of angiosperms.

    PubMed

    López-Fernández, María Paula; Maldonado, Sara

    2015-12-01

    During the diversification of angiosperms, seeds have evolved structural, chemical, molecular and physiologically developing changes that specially affect the nucellus and endosperm. All through seed evolution, programmed cell death (PCD) has played a fundamental role. However, examples of PCD during seed development are limited. The present review examines PCD in integuments, nucellus, suspensor and endosperm in those representative examples of seeds studied to date.

  13. Nanomaterials Toxicity and Cell Death Modalities

    PubMed Central

    De Stefano, Daniela; Carnuccio, Rosa; Maiuri, Maria Chiara

    2012-01-01

    In the last decade, the nanotechnology advancement has developed a plethora of novel and intriguing nanomaterial application in many sectors, including research and medicine. However, many risks have been highlighted in their use, particularly related to their unexpected toxicity in vitro and in vivo experimental models. This paper proposes an overview concerning the cell death modalities induced by the major nanomaterials. PMID:23304518

  14. Lipids and cell death in yeast

    PubMed Central

    Eisenberg, Tobias; Büttner, Sabrina

    2014-01-01

    Understanding lipid-induced malfunction represents a major challenge of today's biomedical research. The connection of lipids to cellular and organ dysfunction, cell death, and disease (often referred to as lipotoxicity) is more complex than the sole lipotoxic effects of excess free fatty acids and requires genetically tractable model systems for mechanistic investigation. We herein summarize recent advances in the field of lipid-induced toxicity that employ the established model system for cell death and aging research of budding yeast Saccharomyces cerevisiae. Studies in yeast have shed light on various aspects of lipotoxicity, including free fatty acid toxicity, sphingolipid-modulated cell death as well as the involvement of cardiolipin and lipid peroxidation in the mitochondrial pathways of apoptosis. Regimens used range from exogenously applied lipids, genetic modulation of lipolysis and triacylglyceride synthesis, variations in sphingolipid/ceramide metabolism as well as changes in peroxisome function by either genetic or pharmacological means. In future, the yeast model of programmed cell death will further contribute to the clarification of crucial questions of lipid-associated malfunction. PMID:24119111

  15. Novel Lipophilic Probe for Detecting Near-Membrane Reactive Oxygen Species Responses and Its Application for Studies of Pancreatic Acinar Cells: Effects of Pyocyanin and L-Ornithine

    PubMed Central

    Chvanov, Michael; Huang, Wei; Jin, Tao; Wen, Li; Armstrong, Jane; Elliot, Vicky; Alston, Ben; Burdyga, Alex; Criddle, David N.; Sutton, Robert

    2015-01-01

    Abstract Aims: The aim of this study was to develop a fluorescent reactive oxygen species (ROS) probe, which is preferentially localized in cellular membranes and displays a strong change in fluorescence upon oxidation. We also aimed to test the performance of this probe for detecting pathophysiologically relevant ROS responses in isolated cells. Results: We introduced a novel lipophilic ROS probe dihydrorhodamine B octadecyl ester (H2RB-C18). We then applied the new probe to characterize the ROS changes triggered by inducers of acute pancreatitis in pancreatic acinar cells. We resolved ROS changes produced by L-ornithine, L-arginine, cholecystokinin-8, acetylcholine, taurolithocholic acid 3-sulfate, palmitoleic acid ethyl ester, and the bacterial toxin pyocyanin. Particularly prominent ROS responses were induced by pyocyanin and L-ornithine. These ROS responses were accompanied by changes in cytosolic Ca2+concentration ([Ca2+]i), mitochondrial membrane potential (ΔΨ), and NAD(P)H concentration. Innovation: The study describes a novel sensitive lipophilic ROS probe. The probe is particularly suitable for detecting ROS in near-membrane regions and therefore for reporting the ROS environment of plasma membrane channels and pumps. Conclusions: In our experimental conditions, the novel probe was more sensitive than 5-(and-6)-chloromethyl-2′,7′-dichlorodihydrofluorescein (CM-H2DCF) and dihydrorhodamine123 (H2R123) and allowed us to resolve ROS responses to secretagogues, pyocyanin, and L-ornithine. Changes in the fluorescence of the new probe were particularly prominent in the peripheral plasma membrane-associated regions. Our findings suggest that the new probe will be a useful tool in studies of the contribution of ROS to the pathophysiology of exocrine pancreas and other organs/tissues. Antioxid. Redox Signal. 22, 451–464. PMID:24635199

  16. Hemoglobins, programmed cell death and somatic embryogenesis.

    PubMed

    Hill, Robert D; Huang, Shuanglong; Stasolla, Claudio

    2013-10-01

    Programmed cell death (PCD) is a universal process in all multicellular organisms. It is a critical component in a diverse number of processes ranging from growth and differentiation to response to stress. Somatic embryogenesis is one such process where PCD is significantly involved. Nitric oxide is increasingly being recognized as playing a significant role in regulating PCD in both mammalian and plant systems. Plant hemoglobins scavenge NO, and evidence is accumulating that events that modify NO levels in plants also affect hemoglobin expression. Here, we review the process of PCD, describing the involvement of NO and plant hemoglobins in the process. NO is an effector of cell death in both plants and vertebrates, triggering the cascade of events leading to targeted cell death that is a part of an organism's response to stress or to tissue differentiation and development. Expression of specific hemoglobins can alter this response in plants by scavenging the NO, thus, interrupting the death process. Somatic embryogenesis is used as a model system to demonstrate how cell-specific expression of different classes of hemoglobins can alter the embryogenic process, affecting hormone synthesis, cell metabolite levels and genes associated with PCD and embryogenic competence. We propose that plant hemoglobins influence somatic embryogenesis and PCD through cell-specific expression of a distinct plant hemoglobin. It is based on the premise that both embryogenic competence and PCD are strongly influenced by cellular NO levels. Increases in cellular NO levels result in elevated Zn(2+) and reactive-oxygen species associated with PCD, but they also result in decreased expression of MYC2, a transcription factor that is a negative effector of indoleacetic acid synthesis, a hormone that positively influences embryogenic competence. Cell-specific hemoglobin expression reduces NO levels as a result of NO scavenging, resulting in cell survival.

  17. Decoding cell death signals in liver inflammation.

    PubMed

    Brenner, Catherine; Galluzzi, Lorenzo; Kepp, Oliver; Kroemer, Guido

    2013-09-01

    Inflammation can be either beneficial or detrimental to the liver, depending on multiple factors. Mild (i.e., limited in intensity and destined to resolve) inflammatory responses have indeed been shown to exert consistent hepatoprotective effects, contributing to tissue repair and promoting the re-establishment of homeostasis. Conversely, excessive (i.e., disproportionate in intensity and permanent) inflammation may induce a massive loss of hepatocytes and hence exacerbate the severity of various hepatic conditions, including ischemia-reperfusion injury, systemic metabolic alterations (e.g., obesity, diabetes, non-alcoholic fatty liver disorders), alcoholic hepatitis, intoxication by xenobiotics and infection, de facto being associated with irreversible liver damage, fibrosis, and carcinogenesis. Both liver-resident cells (e.g., Kupffer cells, hepatic stellate cells, sinusoidal endothelial cells) and cells that are recruited in response to injury (e.g., monocytes, macrophages, dendritic cells, natural killer cells) emit pro-inflammatory signals including - but not limited to - cytokines, chemokines, lipid messengers, and reactive oxygen species that contribute to the apoptotic or necrotic demise of hepatocytes. In turn, dying hepatocytes release damage-associated molecular patterns that-upon binding to evolutionary conserved pattern recognition receptors-activate cells of the innate immune system to further stimulate inflammatory responses, hence establishing a highly hepatotoxic feedforward cycle of inflammation and cell death. In this review, we discuss the cellular and molecular mechanisms that account for the most deleterious effect of hepatic inflammation at the cellular level, that is, the initiation of a massive cell death response among hepatocytes.

  18. Autophagic and apoptotic cell death in amniotic epithelial cells.

    PubMed

    Shen, Z-Y; Li, E-M; Lu, S-Q; Shen, J; Cai, Y-M; Wu, Y-E; Zheng, R-M; Tan, L-J; Xu, L-Y

    2008-11-01

    The aim of this paper is to determine if autophagic cell death is associated with apoptosis and whether it participates in the process of term amniotic rupture. Forty pieces of fresh term amnions, including twenty from a position near the margin of the placentas and twenty from the margin of the naturally ruptured part of the placentas in term gestation were collected, respectively. The amnions were examined by scanning electron microscopy (SEM) and amniotic epithelial (AE) cells were examined by transmission electron microscopy (TEM). Autophagic and apoptotic cell death (PCD) were assayed by laser scanning confocal microscopy (LSCM) or flow cytometry using monodansylcadaverin (MDC) and propidium iodide (PI) stain. BCL(2) and BAX were examined by immunoblotting. Under SEM the amniotic epithelia appeared normal in the position near the placenta. They had an atrophied appearance in the margin of their natural broken parts. In the AE cells PCD was divided into three subtypes by TEM: autophagic cell death with positive stains of MDC and PI; apoptotic cell death; and the mixed type. Quantitative detection showed that there were more death cells, including autophagic and apoptotic, in the AE cells near the ruptured parts than near the placentas. An increased expression of BAX and a decreased expression of BCL(2) protein in the AE cells near the broken margin were observed. Apoptotic and autophagic cell death by the intrinsic pathway are the basic event in the AE cell and they are involved in the cause of membrane rupture of the human amnion in term gestation.

  19. Sickle Cell Trait Not Linked to Early Death in Study

    MedlinePlus

    ... html Sickle Cell Trait Not Linked to Early Death in Study However, black soldiers with the gene ... cell gene variant, are at risk of premature death. People with the sickle cell gene variant do ...

  20. Cell Death and Autophagy in TB

    PubMed Central

    Moraco, Andrew H.; Kornfeld, Hardy

    2014-01-01

    Mycobacterium tuberculosis has succeeded in infecting one third of the human race though inhibition or evasion of innate and adaptive immunity. The pathogen is a facultative intracellular parasite that uses the niche provided by mononuclear phagocytes for its advantage. Complex interactions determine whether the bacillus will or will not be delivered to acidified lysosomes, whether the host phagocyte will survive infection or die, and whether the timing and mode of cell death works to the advantage of the host or the pathogen. Here we discuss cell death and autophagy in TB. These fundamental processes of cell biology feature in all aspects of TB pathogenesis and may be exploited to the treatment or prevention of TB disease. PMID:25453227

  1. Programmed cell death in the plant immune system

    PubMed Central

    Coll, N S; Epple, P; Dangl, J L

    2011-01-01

    Cell death has a central role in innate immune responses in both plants and animals. Besides sharing striking convergences and similarities in the overall evolutionary organization of their innate immune systems, both plants and animals can respond to infection and pathogen recognition with programmed cell death. The fact that plant and animal pathogens have evolved strategies to subvert specific cell death modalities emphasizes the essential role of cell death during immune responses. The hypersensitive response (HR) cell death in plants displays morphological features, molecular architectures and mechanisms reminiscent of different inflammatory cell death types in animals (pyroptosis and necroptosis). In this review, we describe the molecular pathways leading to cell death during innate immune responses. Additionally, we present recently discovered caspase and caspase-like networks regulating cell death that have revealed fascinating analogies between cell death control across both kingdoms. PMID:21475301

  2. A novel role for carbon monoxide as a potent regulator of intracellular Ca2+ and nitric oxide in rat pancreatic acinar cells.

    PubMed

    Moustafa, Amira; Habara, Yoshiaki

    2014-12-01

    Carbon monoxide (CO) is known as an essential gaseous messenger that regulates a wide array of physiological and pathological processes, similar to nitric oxide (NO) and hydrogen sulfide. The aim of the present study was to elucidate the potential role of CO in Ca(2+) homeostasis and to explore the underlying mechanisms in pancreatic acinar cells. The exogenous application of a CO-releasing molecule dose-dependently increased intracellular Ca(2+) concentration ([Ca(2+)]i). A heme oxygenase (HO) inducer increased [Ca(2+)]i in a concentration-dependent manner, and the increase was diminished by an HO inhibitor. The CO-induced [Ca(2+)]i increase persisted in the absence of extracellular Ca(2+), indicating that Ca(2+) release is the initial source for the increase. The inhibition of G protein, phospholipase C (PLC), and inositol 1,4,5-trisphosphate (IP3) receptor diminished the CO-induced [Ca(2+)]i increase. CO upregulated endothelial nitric oxide synthase (eNOS) expression and stimulated NO production, and NOS inhibitor, calmodulin inhibitor, or the absence of extracellular Ca(2+) eliminated the latter response. Blocking the phosphatidylinositol 3-kinase (PI3K)-Akt/protein kinase B (PKB) pathway abolished CO-induced NO production. Pretreatment with an NOS inhibitor, NO scavenger, or soluble guanylate cyclase inhibitor, did not affect the CO-induced [Ca(2+)]i increase, indicating that NO, soluble guanylate cyclase, and cyclic guanosine 5'-monophosphate are not involved in the CO-induced [Ca(2+)]i increase. CO inhibited the secretory responses to CCK-octapeptide or carbachol. We conclude that CO acts as a regulator not only for [Ca(2+)]i homeostasis via a PLC-IP3-IP3 receptor cascade but also for NO production via the calmodulin and PI3K-Akt/PKB pathway, and both CO and NO interact. Moreover, CO may provide potential therapy to ameliorate acute pancreatitis by inhibiting amylase secretion.

  3. Programmed cell death during quinoa perisperm development.

    PubMed

    López-Fernández, María Paula; Maldonado, Sara

    2013-08-01

    At seed maturity, quinoa (Chenopodium quinoa Willd.) perisperm consists of uniform, non-living, thin-walled cells full of starch grains. The objective of the present study was to study quinoa perisperm development and describe the programme of cell death that affects the entire tissue. A number of parameters typically measured during programmed cell death (PCD), such as cellular morphological changes in nuclei and cytoplasm, endoreduplication, DNA fragmentation, and the participation of nucleases and caspase-like proteases in nucleus dismantling, were evaluated; morphological changes in cytoplasm included subcellular aspects related to starch accumulation. This study proved that, following fertilization, the perisperm of quinoa simultaneously accumulates storage reserves and degenerates, both processes mediated by a programme of developmentally controlled cell death. The novel findings regarding perisperm development provide a starting point for further research in the Amaranthaceae genera, such as comparing seeds with and without perisperm, and specifying phylogeny and evolution within this taxon. Wherever possible and appropriate, differences between quinoa perisperm and grass starchy endosperm--a morphologically and functionally similar, although genetically different tissue--were highlighted and discussed.

  4. UV-Induced cell death in plants.

    PubMed

    Nawkar, Ganesh M; Maibam, Punyakishore; Park, Jung Hoon; Sahi, Vaidurya Pratap; Lee, Sang Yeol; Kang, Chang Ho

    2013-01-14

    Plants are photosynthetic organisms that depend on sunlight for energy. Plants respond to light through different photoreceptors and show photomorphogenic development. Apart from Photosynthetically Active Radiation (PAR; 400-700 nm), plants are exposed to UV light, which is comprised of UV-C (below 280 nm), UV-B (280-320 nm) and UV-A (320-390 nm). The atmospheric ozone layer protects UV-C radiation from reaching earth while the UVR8 protein acts as a receptor for UV-B radiation. Low levels of UV-B exposure initiate signaling through UVR8 and induce secondary metabolite genes involved in protection against UV while higher dosages are very detrimental to plants. It has also been reported that genes involved in MAPK cascade help the plant in providing tolerance against UV radiation. The important targets of UV radiation in plant cells are DNA, lipids and proteins and also vital processes such as photosynthesis. Recent studies showed that, in response to UV radiation, mitochondria and chloroplasts produce a reactive oxygen species (ROS). Arabidopsis metacaspase-8 (AtMC8) is induced in response to oxidative stress caused by ROS, which acts downstream of the radical induced cell death (AtRCD1) gene making plants vulnerable to cell death. The studies on salicylic and jasmonic acid signaling mutants revealed that SA and JA regulate the ROS level and antagonize ROS mediated cell death. Recently, molecular studies have revealed genes involved in response to UV exposure, with respect to programmed cell death (PCD).

  5. Ferroptosis is an autophagic cell death process.

    PubMed

    Gao, Minghui; Monian, Prashant; Pan, Qiuhui; Zhang, Wei; Xiang, Jenny; Jiang, Xuejun

    2016-09-01

    Ferroptosis is an iron-dependent form of regulated necrosis. It is implicated in various human diseases, including ischemic organ damage and cancer. Here, we report the crucial role of autophagy, particularly autophagic degradation of cellular iron storage proteins (a process known as ferritinophagy), in ferroptosis. Using RNAi screening coupled with subsequent genetic analysis, we identified multiple autophagy-related genes as positive regulators of ferroptosis. Ferroptosis induction led to autophagy activation and consequent degradation of ferritin and ferritinophagy cargo receptor NCOA4. Consistently, inhibition of ferritinophagy by blockage of autophagy or knockdown of NCOA4 abrogated the accumulation of ferroptosis-associated cellular labile iron and reactive oxygen species, as well as eventual ferroptotic cell death. Therefore, ferroptosis is an autophagic cell death process, and NCOA4-mediated ferritinophagy supports ferroptosis by controlling cellular iron homeostasis. PMID:27514700

  6. The Src kinase Yes is activated in pancreatic acinar cells by gastrointestinal hormones/neurotransmitters, but not pancreatic growth factors, which stimulate its association with numerous other signaling molecules.

    PubMed

    Sancho, Veronica; Nuche-Berenguer, Bernardo; Jensen, R T

    2012-08-01

    For growth factors, cytokines, G-protein-coupled receptors and numerous other stimuli, the Src Family of kinases (SFK) play a central signaling role. SFKs also play an important role in pancreatic acinar cell function including metabolism, secretion, endocytosis, growth and cytoskeletal integrity, although the specific SFKs involved are not fully known. In the present study we used specific antibodies for the SFK, Yes, to determine its presence, activation by pancreatic secretagogues or growth factors, and interaction with cellular signaling cascades mediated by CCK in which Yes participates in to cause acinar cell responses. Yes was identified in acini and secretagogues known to activate phospholipase C (PLC) [CCK, carbachol, bombesin] as well as post-receptor stimulants activating PKC [TPA] or mobilizing cellular calcium [thapsigargin/calcium ionophore (A23187)] each activated Yes. Secretin, which activates adenylate cyclase did not stimulate Yes, nor did pancreatic growth factors. CCK activation of Yes required both high- and low-affinity CCK(1)-receptor states. TPA-/CCK-stimulated Yes activation was completely inhibited by thapsigargin and the PKC inhibitor, GF109203X. CCK/TPA stimulated the association of Yes with focal adhesion kinases (Pyk2, FAK) and its autophosphorylated forms (pY397FAK, pY402Pyk2). Moreover, CCK/TPA stimulated Yes interacted with a number of other signaling proteins, including Shc, PKD, p130(Cas), PI3K and PTEN. This study demonstrates that in rat pancreatic acini, the SFK member Yes is expressed and activated by CCK and other gastrointestinal hormones/neurotransmitters. Because its activation results in the direct activation of many cellular signaling cascades that have been shown to mediate CCK's effect in acinar cell function our results suggest that it is one of the important pancreatic SFKs mediating these effects.

  7. Cell Death and Deubiquitinases: Perspectives in Cancer

    PubMed Central

    Bhattacharya, Seemana

    2014-01-01

    The process of cell death has important physiological implications. At the organism level it is mostly involved in maintenance of tissue homeostasis. At the cellular level, the strategies of cell death may be categorized as either suicide or sabotage. The mere fact that many of these processes are programmed and that these are often deregulated in pathological conditions is seed to thought. The various players that are involved in these pathways are highly regulated. One of the modes of regulation is via post-translational modifications such as ubiquitination and deubiquitination. In this review, we have first dealt with the different modes and pathways involved in cell death and then we have focused on the regulation of several proteins in these signaling cascades by the different deubiquitinating enzymes, in the perspective of cancer. The study of deubiquitinases is currently in a rather nascent stage with limited knowledge both in vitro and in vivo, but the emerging roles of the deubiquitinases in various processes and their specificity have implicated them as potential targets from the therapeutic point of view. This review throws light on another aspect of cancer therapeutics by targeting the deubiquitinating enzymes. PMID:25121098

  8. Decoding cell death signals in liver inflammation.

    PubMed

    Brenner, Catherine; Galluzzi, Lorenzo; Kepp, Oliver; Kroemer, Guido

    2013-09-01

    Inflammation can be either beneficial or detrimental to the liver, depending on multiple factors. Mild (i.e., limited in intensity and destined to resolve) inflammatory responses have indeed been shown to exert consistent hepatoprotective effects, contributing to tissue repair and promoting the re-establishment of homeostasis. Conversely, excessive (i.e., disproportionate in intensity and permanent) inflammation may induce a massive loss of hepatocytes and hence exacerbate the severity of various hepatic conditions, including ischemia-reperfusion injury, systemic metabolic alterations (e.g., obesity, diabetes, non-alcoholic fatty liver disorders), alcoholic hepatitis, intoxication by xenobiotics and infection, de facto being associated with irreversible liver damage, fibrosis, and carcinogenesis. Both liver-resident cells (e.g., Kupffer cells, hepatic stellate cells, sinusoidal endothelial cells) and cells that are recruited in response to injury (e.g., monocytes, macrophages, dendritic cells, natural killer cells) emit pro-inflammatory signals including - but not limited to - cytokines, chemokines, lipid messengers, and reactive oxygen species that contribute to the apoptotic or necrotic demise of hepatocytes. In turn, dying hepatocytes release damage-associated molecular patterns that-upon binding to evolutionary conserved pattern recognition receptors-activate cells of the innate immune system to further stimulate inflammatory responses, hence establishing a highly hepatotoxic feedforward cycle of inflammation and cell death. In this review, we discuss the cellular and molecular mechanisms that account for the most deleterious effect of hepatic inflammation at the cellular level, that is, the initiation of a massive cell death response among hepatocytes. PMID:23567086

  9. Current and Emerging Biomarkers of Cell Death in Human Disease

    PubMed Central

    Li, Kongning; Wu, Deng; Chen, Xi; Zhang, Ting; Zhang, Lu; Yi, Ying; Miao, Zhengqiang; Jin, Nana; Bi, Xiaoman; Wang, Hongwei; Wang, Dong

    2014-01-01

    Cell death is a critical biological process, serving many important functions within multicellular organisms. Aberrations in cell death can contribute to the pathology of human diseases. Significant progress made in the research area enormously speeds up our understanding of the biochemical and molecular mechanisms of cell death. According to the distinct morphological and biochemical characteristics, cell death can be triggered by extrinsic or intrinsic apoptosis, regulated necrosis, autophagic cell death, and mitotic catastrophe. Nevertheless, the realization that all of these efforts seek to pursue an effective treatment and cure for the disease has spurred a significant interest in the development of promising biomarkers of cell death to early diagnose disease and accurately predict disease progression and outcome. In this review, we summarize recent knowledge about cell death, survey current and emerging biomarkers of cell death, and discuss the relationship with human diseases. PMID:24949464

  10. Nonenzymatic cryogenic isolation of therapeutic cells: novel approach for enzyme-free isolation of pancreatic islets using in situ cryopreservation of islets and concurrent selective freeze destruction of acinar tissue.

    PubMed

    Taylor, Michael J; Baicu, Simona C

    2014-01-01

    Cell-based therapies, which all involve processes for procurement and reimplantation of living cells, currently rely upon expensive, inconsistent, and even toxic enzyme digestion processes. A prime example is the preparation of isolated pancreatic islets for the treatment of type 1 diabetes by transplantation. To avoid the inherent pitfalls of these enzymatic methods, we have conceptualized an alternative approach based on the hypothesis that cryobiological techniques can be used for differential freeze destruction of the pancreas (Px) to release islets that are selectively cryopreserved in situ. Pancreata were procured from juvenile pigs using approved procedures. The concept of cryoisolation is based on differential processing of the pancreas in five stages: 1) infiltrating islets in situ preferentially with a cryoprotectant (CPA) cocktail via antegrade perfusion of the major arteries; 2) retrograde ductal infusion of water to distend the acinar; 3) freezing the entire Px solid to < -160°C for storage in liquid nitrogen; 4) mechanically crushing and pulverizing the frozen Px into small fragments; 5) thawing the frozen fragments, filtering, and washing to remove the CPA. Finally, the filtered effluent (cryoisolate) was stained with dithizone for identification of intact islets and with Syto 13/PI for fluorescence viability testing and glucose-stimulated insulin release assessment. As predicted, the cryoisolate contained small fragments of residual tissue comprising an amorphous mass of acinar tissue with largely intact and viable (>90%) embedded islets. Islets were typically larger (range 50-500 µm diameter) than their counterparts isolated from juvenile pigs using conventional enzyme digestion techniques. Functionally, the islets from replicate cryoisolates responded to a glucose challenge with a mean stimulation index = 3.3 ± 0.7. An enzyme-free method of islet isolation relying on in situ cryopreservation of islets with simultaneous freeze

  11. Nonenzymatic cryogenic isolation of therapeutic cells: novel approach for enzyme-free isolation of pancreatic islets using in situ cryopreservation of islets and concurrent selective freeze destruction of acinar tissue.

    PubMed

    Taylor, Michael J; Baicu, Simona C

    2014-01-01

    Cell-based therapies, which all involve processes for procurement and reimplantation of living cells, currently rely upon expensive, inconsistent, and even toxic enzyme digestion processes. A prime example is the preparation of isolated pancreatic islets for the treatment of type 1 diabetes by transplantation. To avoid the inherent pitfalls of these enzymatic methods, we have conceptualized an alternative approach based on the hypothesis that cryobiological techniques can be used for differential freeze destruction of the pancreas (Px) to release islets that are selectively cryopreserved in situ. Pancreata were procured from juvenile pigs using approved procedures. The concept of cryoisolation is based on differential processing of the pancreas in five stages: 1) infiltrating islets in situ preferentially with a cryoprotectant (CPA) cocktail via antegrade perfusion of the major arteries; 2) retrograde ductal infusion of water to distend the acinar; 3) freezing the entire Px solid to < -160°C for storage in liquid nitrogen; 4) mechanically crushing and pulverizing the frozen Px into small fragments; 5) thawing the frozen fragments, filtering, and washing to remove the CPA. Finally, the filtered effluent (cryoisolate) was stained with dithizone for identification of intact islets and with Syto 13/PI for fluorescence viability testing and glucose-stimulated insulin release assessment. As predicted, the cryoisolate contained small fragments of residual tissue comprising an amorphous mass of acinar tissue with largely intact and viable (>90%) embedded islets. Islets were typically larger (range 50-500 µm diameter) than their counterparts isolated from juvenile pigs using conventional enzyme digestion techniques. Functionally, the islets from replicate cryoisolates responded to a glucose challenge with a mean stimulation index = 3.3 ± 0.7. An enzyme-free method of islet isolation relying on in situ cryopreservation of islets with simultaneous freeze

  12. Cell Death Control by Matrix Metalloproteinases.

    PubMed

    Zimmermann, Dirk; Gomez-Barrera, Juan A; Pasule, Christian; Brack-Frick, Ursula B; Sieferer, Elke; Nicholson, Tim M; Pfannstiel, Jens; Stintzi, Annick; Schaller, Andreas

    2016-06-01

    In contrast to mammalian matrix metalloproteinases (MMPs) that play important roles in the remodeling of the extracellular matrix in animals, the proteases responsible for dynamic modifications of the plant cell wall are largely unknown. A possible involvement of MMPs was addressed by cloning and functional characterization of Sl2-MMP and Sl3-MMP from tomato (Solanum lycopersicum). The two tomato MMPs were found to resemble mammalian homologs with respect to gelatinolytic activity, substrate preference for hydrophobic amino acids on both sides of the scissile bond, and catalytic properties. In transgenic tomato seedlings silenced for Sl2/3-MMP expression, necrotic lesions were observed at the base of the hypocotyl. Cell death initiated in the epidermis and proceeded to include outer cortical cell layers. In later developmental stages, necrosis spread, covering the entire stem and extending into the leaves of MMP-silenced plants. The subtilisin-like protease P69B was identified as a substrate of Sl2- and Sl3-MMP. P69B was shown to colocalize with Sl-MMPs in the apoplast of the tomato hypocotyl, it exhibited increased stability in transgenic plants silenced for Sl-MMP activity, and it was cleaved and inactivated by Sl-MMPs in vitro. The induction of cell death in Sl2/3-MMP-silenced plants depended on P69B, indicating that Sl2- and Sl3-MMP act upstream of P69B in an extracellular proteolytic cascade that contributes to the regulation of cell death in tomato. PMID:27208293

  13. Mechanism of Cytosolic Phospholipase A(2) Activation in Ghrelin Protection of Salivary Gland Acinar Cells against Ethanol Cytotoxicity.

    PubMed

    Slomiany, Bronislaw L; Slomiany, Amalia

    2010-01-01

    Ghrelin, a peptide hormone, newly identified in oral mucosal tissues, has emerged recently as an important mediator of the processes of mucosal defense. Here, we report on the mechanism of ghrelin protection against ethanol cytotoxicity in rat sublingual salivary gland cells. The protective effect of ghrelin was associated with the increase in NO and PGE2, and upregulation in cytosolic phospholipase A(2) (cPLA(2)) activity and arachidonic acid (AA) release. The loss in countering effect of ghrelin occurred with cNOS inhibitor, L-NAME, as well as indomethacin and COX-1 inhibitor, SC-560, while COX-2 inhibitor, NS-398, and iNOS inhibitor, 1400W, had no effect. The effect of L-NAME was reflected in the inhibition of ghrelin-induced cell capacity for NO production, cPLA(2) activation and PGE2 generation, whereas indomethacin caused only the inhibition in PGE2. Moreover, the ghrelin-induced up-regulation in AA release was reflected in the cPLA(2) phosphorylation and S-nitrosylation. Inhibition in ghrelin-induced S-nitrosylation was attained with L-NAME, whereas the ERK inhibitor, PD98059, caused the blockage in cPLA(2) protein phosphorylation as well as S-nitrosylation. Thus, ghrelin protection of salivary gland cells against ethanol involves cNOS-derived NO induction of cPLA(2) activation through S-nitrosylation for the increase in AA release at the site of COX-1 action for PGE2 synthesis.

  14. Autophagic cell death: Loch Ness monster or endangered species?

    PubMed

    Shen, Han-Ming; Codogno, Patrice

    2011-05-01

    The concept of autophagic cell death was first established based on observations of increased autophagic markers in dying cells. The major limitation of such a morphology-based definition of autophagic cell death is that it fails to establish the functional role of autophagy in the cell death process, and thus contributes to the confusion in the literature regarding the role of autophagy in cell death and cell survival. Here we propose to define autophagic cell death as a modality of non-apoptotic or necrotic programmed cell death in which autophagy serves as a cell death mechanism, upon meeting the following set of criteria: (i) cell death occurs without the involvement of apoptosis; (ii) there is an increase of autophagic flux, and not just an increase of the autophagic markers, in the dying cells; and (iii) suppression of autophagy via both pharmacological inhibitors and genetic approaches is able to rescue or prevent cell death. In light of this new definition, we will discuss some of the common problems and difficulties in the study of autophagic cell death and also revisit some well-reported cases of autophagic cell death, aiming to achieve a better understanding of whether autophagy is a real killer, an accomplice or just an innocent bystander in the course of cell death. At present, the physiological relevance of autophagic cell death is mainly observed in lower eukaryotes and invertebrates such as Dictyostelium discoideum and Drosophila melanogaster. We believe that such a clear definition of autophagic cell death will help us study and understand the physiological or pathological relevance of autophagic cell death in mammals.

  15. Cell death goes LIVE: technological advances in real-time tracking of cell death.

    PubMed

    Skommer, Joanna; Darzynkiewicz, Zbigniew; Wlodkowic, Donald

    2010-06-15

    Cell population can be viewed as a quantum system, which like Schrödinger's cat exists as a combination of survival- and death-allowing states. Tracking and understanding cell-to-cell variability in processes of high spatio-temporal complexity such as cell death is at the core of current systems biology approaches. As probabilistic modeling tools attempt to impute information inaccessible by current experimental approaches, advances in technologies for single-cell imaging and omics (proteomics, genomics, metabolomics) should go hand in hand with the computational efforts. Over the last few years we have made exciting technological advances that allow studies of cell death dynamically in real-time and with the unprecedented accuracy. These approaches are based on innovative fluorescent assays and recombinant proteins, bioelectrical properties of cells, and more recently also on state-of-the-art optical spectroscopy. Here, we review current status of the most innovative analytical technologies for dynamic tracking of cell death, and address the interdisciplinary promises and future challenges of these methods.

  16. ACCELERATED CELL DEATH2 suppresses mitochondrial oxidative bursts and modulates cell death in Arabidopsis

    PubMed Central

    Pattanayak, Gopal K.; Venkataramani, Sujatha; Hortensteiner, Stefan; Kunz, Lukas; Christ, Bastien; Moulin, Michael; Smith, Alison G.; Okamoto, Yukihiro; Tamiaki, Hitoshi; Sugishima, Masakazu; Greenberg, Jean T.

    2012-01-01

    SUMMARY The Arabidopsis ACCELERATED CELL DEATH 2 (ACD2) protein protects cells from programmed cell death (PCD) caused by endogenous porphyrin-related molecules like red chlorophyll catabolite or exogenous protoporphyrin IX. We previously found that during bacterial infection, ACD2, a chlorophyll breakdown enzyme, localizes to both chloroplasts and mitochondria in leaves. Additionally, acd2 cells show mitochondrial dysfunctions. In plants with acd2 and ACD2+ sectors, ACD2 functions cell autonomously, implicating a pro-death ACD2 substrate as cell non-autonomous in promoting spreading PCD. ACD2 targeted solely to mitochondria can reduce the accumulation of an ACD2 substrate that originates in chloroplasts, indicating that ACD2 substrate molecules are likely mobile within cells. Two different light-dependent reactive oxygen bursts in mitochondria play prominent and causal roles in the acd2 PCD phenotype. Finally, ACD2 can complement acd2 when targeted to mitochondria or chloroplasts, respectively, as long as it is catalytically active; the ability to bind substrate is not sufficient for ACD2 to function in vitro or in vivo. Together the data suggest that ACD2 localizes dynamically during infection to protect cells from pro-death mobile substrate molecules, some of which may originate in chloroplasts, but have major effects on mitochondria. PMID:21988537

  17. Accelerated cell death 2 suppresses mitochondrial oxidative bursts and modulates cell death in Arabidopsis.

    PubMed

    Pattanayak, Gopal K; Venkataramani, Sujatha; Hortensteiner, Stefan; Kunz, Lukas; Christ, Bastien; Moulin, Michael; Smith, Alison G; Okamoto, Yukihiro; Tamiaki, Hitoshi; Sugishima, Masakazu; Greenberg, Jean T

    2012-02-01

    The Arabidopsis ACCELERATED CELL DEATH 2 (ACD2) protein protects cells from programmed cell death (PCD) caused by endogenous porphyrin-related molecules like red chlorophyll catabolite or exogenous protoporphyrin IX. We previously found that during bacterial infection, ACD2, a chlorophyll breakdown enzyme, localizes to both chloroplasts and mitochondria in leaves. Additionally, acd2 cells show mitochondrial dysfunction. In plants with acd2 and ACD2 (+) sectors, ACD2 functions cell autonomously, implicating a pro-death ACD2 substrate as being cell non-autonomous in promoting the spread of PCD. ACD2 targeted solely to mitochondria can reduce the accumulation of an ACD2 substrate that originates in chloroplasts, indicating that ACD2 substrate molecules are likely to be mobile within cells. Two different light-dependent reactive oxygen bursts in mitochondria play prominent and causal roles in the acd2 PCD phenotype. Finally, ACD2 can complement acd2 when targeted to mitochondria or chloroplasts, respectively, as long as it is catalytically active: the ability to bind substrate is not sufficient for ACD2 to function in vitro or in vivo. Together, the data suggest that ACD2 localizes dynamically during infection to protect cells from pro-death mobile substrate molecules, some of which may originate in chloroplasts, but have major effects on mitochondria.

  18. Comparison of Types of Cell Death: Apoptosis and Necrosis.

    ERIC Educational Resources Information Center

    Manning, Francis; Zuzel, Katherine

    2003-01-01

    Cell death is an essential factor in many biological processes including development. Discusses two types of cell death: (1) necrosis (induced by sodium azide); and (2) apoptosis (induced by sodium chromate). Illustrates key features that differ between these two types of cells death including loss of membrane integrity and internucleosomal DNA…

  19. Cellular Stress Responses: Cell Survival and Cell Death

    PubMed Central

    Fulda, Simone; Gorman, Adrienne M.; Hori, Osamu; Samali, Afshin

    2010-01-01

    Cells can respond to stress in various ways ranging from the activation of survival pathways to the initiation of cell death that eventually eliminates damaged cells. Whether cells mount a protective or destructive stress response depends to a large extent on the nature and duration of the stress as well as the cell type. Also, there is often the interplay between these responses that ultimately determines the fate of the stressed cell. The mechanism by which a cell dies (i.e., apoptosis, necrosis, pyroptosis, or autophagic cell death) depends on various exogenous factors as well as the cell's ability to handle the stress to which it is exposed. The implications of cellular stress responses to human physiology and diseases are manifold and will be discussed in this review in the context of some major world health issues such as diabetes, Parkinson's disease, myocardial infarction, and cancer. PMID:20182529

  20. Inhibition of caspases prevents ototoxic and ongoing hair cell death

    NASA Technical Reports Server (NTRS)

    Matsui, Jonathan I.; Ogilvie, Judith M.; Warchol, Mark E.

    2002-01-01

    Sensory hair cells die after acoustic trauma or ototoxic insults, but the signal transduction pathways that mediate hair cell death are not known. Here we identify several important signaling events that regulate the death of vestibular hair cells. Chick utricles were cultured in media supplemented with the ototoxic antibiotic neomycin and selected pharmacological agents that influence signaling molecules in cell death pathways. Hair cells that were treated with neomycin exhibited classically defined apoptotic morphologies such as condensed nuclei and fragmented DNA. Inhibition of protein synthesis (via treatment with cycloheximide) increased hair cell survival after treatment with neomycin, suggesting that hair cell death requires de novo protein synthesis. Finally, the inhibition of caspases promoted hair cell survival after neomycin treatment. Sensory hair cells in avian vestibular organs also undergo continual cell death and replacement throughout mature life. It is unclear whether the loss of hair cells stimulates the proliferation of supporting cells or whether the production of new cells triggers the death of hair cells. We examined the effects of caspase inhibition on spontaneous hair cell death in the chick utricle. Caspase inhibitors reduced the amount of ongoing hair cell death and ongoing supporting cell proliferation in a dose-dependent manner. In isolated sensory epithelia, however, caspase inhibitors did not affect supporting cell proliferation directly. Our data indicate that ongoing hair cell death stimulates supporting cell proliferation in the mature utricle.

  1. Apoptosis, oncosis, and necrosis. An overview of cell death.

    PubMed Central

    Majno, G.; Joris, I.

    1995-01-01

    The historical development of the cell death concept is reviewed, with special attention to the origin of the terms necrosis, coagulation necrosis, autolysis, physiological cell death, programmed cell death, chromatolysis (the first name of apoptosis in 1914), karyorhexis, karyolysis, and cell suicide, of which there are three forms: by lysosomes, by free radicals, and by a genetic mechanism (apoptosis). Some of the typical features of apoptosis are discussed, such as budding (as opposed to blebbing and zeiosis) and the inflammatory response. For cell death not by apoptosis the most satisfactory term is accidental cell death. Necrosis is commonly used but it is not appropriate, because it does not indicate a form of cell death but refers to changes secondary to cell death by any mechanism, including apoptosis. Abundant data are available on one form of accidental cell death, namely ischemic cell death, which can be considered an entity of its own, caused by failure of the ionic pumps of the plasma membrane. Because ischemic cell death (in known models) is accompanied by swelling, the name oncosis is proposed for this condition. The term oncosis (derived from ónkos, meaning swelling) was proposed in 1910 by von Reckling-hausen precisely to mean cell death with swelling. Oncosis leads to necrosis with karyolysis and stands in contrast to apoptosis, which leads to necrosis with karyorhexis and cell shrinkage. Images Figure 1 Figure 2 Figure 3 Figure 5 Figure 6 Figure 7 Figure 8 PMID:7856735

  2. Histone deacetylase inhibitors and cell death

    PubMed Central

    Zhang, Jing; Zhong, Qing

    2014-01-01

    Histone deacetylases (HDACs) are a vast family of enzymes involved in chromatin remodeling and have crucial roles in numerous biological processes, largely through their repressive influence on transcription. In addition to modifying histones, HDACs also target many other non-histone protein substrates to regulate gene expression. Recently, HDACs have gained growing attention as HDAC-inhibiting compounds are being developed as promising cancer therapeutics. Histone deacetylase inhibitors (HDACi) have been shown to induce differentiation, cell cycle arrest, apoptosis, autophagy and necrosis in a variety of transformed cell lines. In this review, we mainly discuss how HDACi may elicit a therapeutic response to human cancers through different cell death pathways, in particular, apoptosis and autophagy. PMID:24898083

  3. Programmed Cell Death in Unicellular Phytoplankton.

    PubMed

    Bidle, Kay D

    2016-07-11

    Unicellular, planktonic, prokaryotic and eukaryotic photoautotrophs (phytoplankton) have an ancient evolutionary history on Earth during which time they have played key roles in the regulation of marine food webs, biogeochemical cycles, and Earth's climate. Since they represent the basis of aquatic ecosystems, the manner in which phytoplankton die critically determines the flow and fate of photosynthetically fixed organic matter (and associated elements), ultimately constraining nutrient flow. Programmed cell death (PCD) and associated pathway genes, which are triggered by a variety of abiotic (nutrient, light, osmotic) and biotic (virus infection, allelopathy) environmental stresses, have an integral grip on cell fate, and have shaped the ecological success and evolutionary trajectory of diverse phytoplankton lineages. A combination of physiological, biochemical, and genetic techniques in model algal systems has demonstrated a conserved molecular and mechanistic framework of stress surveillance, signaling, and death activation pathways, involving collective and coordinated participation of organelles, redox enzymes, metabolites, and caspase-like proteases. This mechanistic understanding has provided insight into the integration of sensing and transduction of stress signals into cellular responses, and the mechanistic interfaces between PCD, cell stress and virus infection pathways. It has also provided insight into the evolution of PCD in unicellular photoautotrophs, the impact of PCD on the fate of natural phytoplankton assemblages and its role in aquatic biogeochemical cycles. PMID:27404255

  4. Programmed Cell Death in Unicellular Phytoplankton.

    PubMed

    Bidle, Kay D

    2016-07-11

    Unicellular, planktonic, prokaryotic and eukaryotic photoautotrophs (phytoplankton) have an ancient evolutionary history on Earth during which time they have played key roles in the regulation of marine food webs, biogeochemical cycles, and Earth's climate. Since they represent the basis of aquatic ecosystems, the manner in which phytoplankton die critically determines the flow and fate of photosynthetically fixed organic matter (and associated elements), ultimately constraining nutrient flow. Programmed cell death (PCD) and associated pathway genes, which are triggered by a variety of abiotic (nutrient, light, osmotic) and biotic (virus infection, allelopathy) environmental stresses, have an integral grip on cell fate, and have shaped the ecological success and evolutionary trajectory of diverse phytoplankton lineages. A combination of physiological, biochemical, and genetic techniques in model algal systems has demonstrated a conserved molecular and mechanistic framework of stress surveillance, signaling, and death activation pathways, involving collective and coordinated participation of organelles, redox enzymes, metabolites, and caspase-like proteases. This mechanistic understanding has provided insight into the integration of sensing and transduction of stress signals into cellular responses, and the mechanistic interfaces between PCD, cell stress and virus infection pathways. It has also provided insight into the evolution of PCD in unicellular photoautotrophs, the impact of PCD on the fate of natural phytoplankton assemblages and its role in aquatic biogeochemical cycles.

  5. Macrophage cell death upon intracellular bacterial infection

    PubMed Central

    Lai, Xin-He; Xu, Yunsheng; Chen, Xiao-Ming; Ren, Yi

    2015-01-01

    Macrophage-pathogen interaction is a complex process and the outcome of this tag-of-war for both sides is to live or die. Without attempting to be comprehensive, this review will discuss the complexity and significance of the interaction outcomes between macrophages and some facultative intracellular bacterial pathogens as exemplified by Francisella, Salmonella, Shigella and Yersinia. Upon bacterial infection, macrophages can die by a variety of ways, such as apoptosis, autophagic cell death, necrosis, necroptosis, oncosis, pyronecrosis, pyroptosis etc, which is the focus of this review. PMID:26690967

  6. Acinar-to-ductal metaplasia accompanies c-myc-induced exocrine pancreatic cancer progression in transgenic rodents.

    PubMed

    Grippo, Paul J; Sandgren, Eric P

    2012-09-01

    Several important characteristics of exocrine pancreatic tumor pathogenesis remain incompletely defined, including identification of the cell of origin. Most human pancreatic neoplasms are ductal adenocarcinomas. However, acinar cells have been proposed as the source of some ductal neoplasms through a process of acinar-to-ductal metaplasia. The oncogenic transcription factor c-myc is associated with human pancreatic neoplasms. Transgenic mice overexpressing c-myc under control of acinar cell-specific elastase (Ela) gene regulatory elements not only develop acinar cell carcinomas but also mixed neoplasms that display both acinar-like neoplastic cells and duct-like neoplastic cells. In this report, we demonstrate that, first, c-myc is sufficient to induce acinar hyperplasia, though neoplastic lesions develop focally. Second, cell proliferation remains elevated in the neoplastic duct cell compartment of mixed neoplasms. Third, the proliferation/apoptosis ratio in cells from all lesion types remains constant, suggesting that differential regulation of these processes is not a feature of cancer progression in this model. Fourth, before the development of mixed neoplasms, there is transcriptional activation of the duct cell-specific cytokeratin-19 gene promoter in multicellular foci of amylase-positive acinar neoplasms. This observation provides direct evidence for metaplasia as the mechanism underlying development of ductal neoplastic cells within the context of an acinar neoplasm and suggests that the stimulus for this transformation acts over a multicellular domain or field within a neoplasm. Finally, focal ductal elements develop in some acinar cell carcinomas in Ela-c-myc transgenic rats, indicating that myc-associated acinar-to-ductal metaplasia is not restricted to the mouse.

  7. Acinar adenocarcinoma —

    Cancer.gov

    Composed of predominately glandular structures, lined by cuboidal to tall cells, sometimes with mucous production. Cases with the presence of at least 10% of squamous or neuroendocrine component should be allocated to adenosquamous or neuroendocrine carcinoma, respectively.

  8. Active oxygen and cell death in cereal aleurone cells.

    PubMed

    Fath, Angelika; Bethke, Paul; Beligni, Veronica; Jones, Russell

    2002-05-01

    The cereal aleurone layer is a secretory tissue whose function is regulated by gibberellic acid (GA) and abscisic acid (ABA). Aleurone cells lack functional chloroplasts, thus excluding photosynthesis as a source of active oxygen species (AOS) in cell death. Incubation of barley aleurone layers or protoplasts in GA initiated the cell death programme, but incubation in ABA delays programmed cell death (PCD). Light, especially blue and UV-A light, and H(2)O(2) accelerate PCD of GA-treated aleurone cells, but ABA-treated aleurone cells are refractory to light and H(2)O(2) and are not killed. It was shown that light elevated intracellular H(2)O(2), and that the rise in H(2)O(2) was greater in GA-treated cells compared to cells in ABA. Experiments with antioxidants show that PCD in aleurone is probably regulated by AOS. The sensitivity of GA-treated aleurone to light and H(2)O(2) is a result of lowered amounts of enzymes that metabolize AOS. mRNAs encoding catalase, ascorbate peroxidase and superoxide dismutase are all reduced during 6-18 h of incubation in GA, but these mRNAs were present in higher amounts in cells incubated in ABA. The amounts of protein and enzyme activities encoded by these mRNAs were also dramatically reduced in GA-treated cells. Aleurone cells store and metabolize neutral lipids via the glyoxylate cycle in response to GA, and glyoxysomes are one potential source of AOS in the GA-treated cells. Mitochondria are another potential source of AOS in GA-treated cells. AOS generated by these organelles bring about membrane rupture and cell death.

  9. Cell Death and DAMPs in Acute Pancreatitis

    PubMed Central

    Kang, Rui; Lotze, Michael T; Zeh, Herbert J; Billiar, Timothy R; Tang, Daolin

    2014-01-01

    Cell death and inflammation are key pathologic responses of acute pancreatitis (AP), the leading cause of hospital admissions for gastrointestinal disorders. It is becoming increasingly clear that damage-associated molecular pattern molecules (DAMPs) play an important role in the pathogenesis of AP by linking local tissue damage to systemic inflammation syndrome. Endogenous DAMPs released from dead, dying or injured cells initiate and extend sterile inflammation via specific pattern recognition receptors. Inhibition of the release and activity of DAMPs (for example, high mobility group box 1, DNA, histones and adenosine triphosphate) provides significant protection against experimental AP. Moreover, increased serum levels of DAMPs in patients with AP correlate with disease severity. These findings provide novel insight into the mechanism, diagnosis and management of AP. DAMPs might be an attractive therapeutic target in AP. PMID:25105302

  10. Cell Death Signaling and Anticancer Therapy

    PubMed Central

    Galluzzi, Lorenzo; Vitale, Ilio; Vacchelli, Erika; Kroemer, Guido

    2011-01-01

    For a long time, it was commonly believed that efficient anticancer regimens would either trigger the apoptotic demise of tumor cells or induce a permanent arrest in the G1 phase of the cell cycle, i.e., senescence. The recent discovery that necrosis can occur in a regulated fashion and the increasingly more precise characterization of the underlying molecular mechanisms have raised great interest, as non-apoptotic pathways might be instrumental to circumvent the resistance of cancer cells to conventional, pro-apoptotic therapeutic regimens. Moreover, it has been shown that some anticancer regimens engage lethal signaling cascades that can ignite multiple oncosuppressive mechanisms, including apoptosis, necrosis, and senescence. Among these signaling pathways is mitotic catastrophe, whose role as a bona fide cell death mechanism has recently been reconsidered. Thus, anticancer regimens get ever more sophisticated, and often distinct strategies are combined to maximize efficacy and minimize side effects. In this review, we will discuss the importance of apoptosis, necrosis, and mitotic catastrophe in the response of tumor cells to the most common clinically employed and experimental anticancer agents. PMID:22655227

  11. Protection of islet cells from inflammatory cell death in vitro.

    PubMed Central

    Burkart, V; Kolb, H

    1993-01-01

    Islet cells cocultured with activated macrophages are lysed within 15 h in vitro. We showed previously that nitric oxide generated by macrophages is a major mediator of islet cell death. We have now probed several pathways to interfere with the chain of events leading to islet cell death. Scavenging of extracellular oxygen radicals by superoxide dismutase and catalase did not improve islet cell survival. Scavenging of extra- and intracellular oxygen radicals by two potent substances, citiolone and dimethyl-thiourea, also did not reduce islet cell lysis, while a lipid-soluble scavenger, probucol, provided partial protection. These findings argue against a synergistic action of nitric oxide and oxygen radicals in islet cell toxicity. The inhibition of poly(ADP-ribose)polymerase by 3-aminobenzamide significantly improved islet cell survival. Selective inhibitors of cyclooxygenase, such as indomethacin or acetylsalicylic acid, did not improve islet cell survival. Full protection was seen in the presence of NDGA, an inhibitor of lipoxygenase, and partial suppression was caused by BW755c, an inhibitor of both lipoxygenase and cyclooxygenase. We conclude that inflammatory islet cell death caused by activated macrophages involves the activation of arachidonic acid metabolism and of poly(ADP-ribose)polymerase, but that scavenging of oxygen free radicals provides little protection from lysis. PMID:8348756

  12. Sulfur dioxide induced programmed cell death in Vicia guard cells.

    PubMed

    Yi, Huilan; Yin, Jingjing; Liu, Xin; Jing, Xiuqing; Fan, Sanhong; Zhang, Hufang

    2012-04-01

    Sulfur dioxide (SO(2)) induced nuclear condensation and nuclear fragmentation and rapid loss of guard cell viability in detached epidermis of Vicia leaves at concentrations of 1 mM and higher (3 h exposure). Caspase inhibitors Z-Asp-CH(2)-DCB (0.1 mM) and TLCK (0.1 mM) markedly suppressed SO(2)-induced cell death. The typical nuclear morphological changes and the inhibition effects of caspase inhibitors suggest the activation of a programmed cell death (PCD) pathway. SO(2)-induced cell death can be blocked by either antioxidants (0.1 mM AsA or 200 U/mL CAT) or Ca(2+) antagonists (0.1mM EGTA or LaCl(3)). AsA and CAT also blocked SO(2)-induced ROS production and [Ca(2+)](cyt) increase. However, EGTA and LaCl(3) can inhibit SO(2)-induced [Ca(2+)](cyt) increase, but cannot suppress SO(2)-induced ROS production. Our results indicate that high concentrations of SO(2) induce guard cell death via a PCD pathway through ROS mediating [Ca(2+)](cyt) elevation, which causes harmful effects to plants.

  13. Xylem cell death: emerging understanding of regulation and function.

    PubMed

    Bollhöner, Benjamin; Prestele, Jakob; Tuominen, Hannele

    2012-02-01

    Evolutionary, as well as genetic, evidence suggests that vascular development evolved originally as a cell death programme that allowed enhanced movement of water in the extinct protracheophytes, and that secondary wall formation in the water-conducting cells evolved afterwards, providing mechanical support for effective long-distance transport of water. The extant vascular plants possess a common regulatory network to coordinate the different phases of xylem maturation, including secondary wall formation, cell death, and finally autolysis of the cell contents, by the action of recently identified NAC domain transcription factors. Consequently, xylem cell death is an inseparable part of the xylem maturation programme, making it difficult to uncouple cell death mechanistically from secondary wall formation, and thus identify the key factors specifically involved in regulation of cell death. Current knowledge suggests that the necessary components for xylem cell death are produced early during xylem differentiation, and cell death is prevented through the action of inhibitors and storage of hydrolytic enzymes in inactive forms in compartments such as the vacuole. Bursting of the central vacuole triggers autolytic hydrolysis of the cell contents, which ultimately leads to cell death. This cascade of events varies between the different xylem cell types. The water-transporting tracheary elements rely on a rapid cell death programme, with hydrolysis of cell contents taking place for the most part, if not entirely, after vacuolar bursting, while the xylem fibres disintegrate cellular contents at a slower pace, well before cell death. This review includes a detailed description of cell morphology, function of plant growth regulators, such as ethylene and thermospermine, and the action of hydrolytic nucleases and proteases during cell death of the different xylem cell types.

  14. Pyroptotic cell death defends against intracellular pathogens

    PubMed Central

    Jorgensen, Ine; Miao, Edward A

    2015-01-01

    Summary Inflammatory caspases play a central role in innate immunity by responding to cytosolic signals and initiating a twofold response. First, caspase-1 induces the activation and secretion of the two prominent pro-inflammatory cytokines, interleukin-1β (IL-1β) and IL-18. Second, either caspase-1 or caspase-11 can trigger a form of lytic, programmed cell death called pyroptosis. Pyroptosis operates to remove the replication niche of intracellular pathogens, making them susceptible to phagocytosis and killing by a secondary phagocyte. However, aberrant, systemic activation of pyroptosis in vivo may contribute to sepsis. Emphasizing the efficiency of inflammasome detection of microbial infections, many pathogens have evolved to avoid or subvert pyroptosis. This review focuses on molecular and morphological characteristics of pyroptosis and the individual inflammasomes and their contribution to defense against infection in mice and humans. PMID:25879289

  15. Caspases Connect Cell-Death Signaling to Organismal Homeostasis.

    PubMed

    Galluzzi, Lorenzo; López-Soto, Alejandro; Kumar, Sharad; Kroemer, Guido

    2016-02-16

    Some forms of regulated cell death, such as apoptosis, are precipitated by the activation of cysteine proteases of the caspase family, including caspase 8, 9, and 3. Other caspases, such as caspase 1 and 4, are well known for their pro-inflammatory functions but regulate cell death in a limited number of pathophysiological settings. Accumulating evidence suggests that the most conserved function of mammalian caspases is not to control cell death sensu stricto, but to regulate inflammatory and immune reactions to dying cells and infectious challenges. Here, we review the molecular and cellular mechanisms though which mammalian caspases connect cell-death signaling to the maintenance of organismal homeostasis.

  16. Cell death by autophagy: facts and apparent artefacts

    PubMed Central

    Denton, D; Nicolson, S; Kumar, S

    2012-01-01

    Autophagy (the process of self-digestion by a cell through the action of enzymes originating within the lysosome of the same cell) is a catabolic process that is generally used by the cell as a mechanism for quality control and survival under nutrient stress conditions. As autophagy is often induced under conditions of stress that could also lead to cell death, there has been a propagation of the idea that autophagy can act as a cell death mechanism. Although there is growing evidence of cell death by autophagy, this type of cell death, often called autophagic cell death, remains poorly defined and somewhat controversial. Merely the presence of autophagic markers in a cell undergoing death does not necessarily equate to autophagic cell death. Nevertheless, studies involving genetic manipulation of autophagy in physiological settings provide evidence for a direct role of autophagy in specific scenarios. This article endeavours to summarise these physiological studies where autophagy has a clear role in mediating the death process and discusses the potential significance of cell death by autophagy. PMID:22052193

  17. Stroke and cardiac cell death: Two peas in a pod.

    PubMed

    Gonzales-Portillo, Chiara; Ishikawa, Hiroto; Shinozuka, Kazutaka; Tajiri, Naoki; Kaneko, Yuji; Borlongan, Cesar V

    2016-03-01

    A close pathological link between stroke brain and heart failure may exist. Here, we discuss relevant laboratory and clinical reports demonstrating neural and cardiac myocyte cell death following ischemic stroke. Although various overlapping risk factors exist between cerebrovascular incidents and cardiac incidents, stroke therapy has largely neglected the cardiac pathological consequences. Recent preclinical stroke studies have implicated an indirect cell death pathway, involving toxic molecules, that originates from the stroke brain and produces cardiac cell death. In concert, previous laboratory reports have revealed a reverse cell death cascade, in that cardiac arrest leads to ischemic cell death in the brain. A deeper understanding of the crosstalk of cell death pathways between stroke and cardiac failure will facilitate the development of novel treatments designed to arrest the global pathology of both diseases thereby improving the clinical outcomes of patients diagnosed with stroke and heart failure.

  18. Cell block eleven, looking from the "Death Row" exercise yard, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Cell block eleven, looking from the "Death Row" exercise yard, facing north (note cell block fifteen to the right and cell block fourteen in the distance_ - Eastern State Penitentiary, 2125 Fairmount Avenue, Philadelphia, Philadelphia County, PA

  19. Neurodegeneration in Lurcher mice occurs via multiple cell death pathways.

    PubMed

    Doughty, M L; De Jager, P L; Korsmeyer, S J; Heintz, N

    2000-05-15

    Lurcher (Lc) is a gain-of-function mutation in the delta2 glutamate receptor (GRID2) that results in the cell-autonomous death of cerebellar Purkinje cells in heterozygous lurcher (+/Lc) mice. This in turn triggers the massive loss of afferent granule cells during the first few postnatal weeks. Evidence suggests that the death of Purkinje cells as a direct consequence of GRID2(Lc) activation and the secondary death of granule cells because of target deprivation occur by apoptosis. We have used mice carrying null mutations of both the Bax and p53 genes to examine the roles of these genes in cell loss in lurcher animals. The absence of Bax delayed Purkinje cell death in response to the GRID2(Lc) mutation and permanently rescued the secondary death of granule cells. In contrast, the p53 deletion had no effect on either cell death pathway. Our results demonstrate that target deprivation induces a Bax-dependent, p53-independent cell death response in cerebellar granule cells in vivo. In contrast, Bax plays a minor role in GRID2(Lc)-mediated Purkinje cell death.

  20. Light regulation of cadmium-induced cell death in Arabidopsis

    PubMed Central

    Smith, Sarah J; Wang, Yun; Slabas, Antoni R; Chivasa, Stephen

    2014-01-01

    Cadmium is an environmental pollutant with deleterious effects on both prokaryotic and eukaryotic organisms. In plants, the effects of cadmium toxicity are concentration dependent; lower doses destabilize many physiological processes and inhibit cell growth and multiplication, while higher doses evoke a more severe response that triggers activation of cell death. We recently investigated the effects of light on cadmium toxicity in Arabidopsis using a cell suspension culture system. Although not affecting the inhibitory effects on cell multiplication, we found that light is a powerful regulator of Cd-induced cell death. A very specific proteomic response, which was clearly controlled by light, preceded cell death. Here we discuss the implications of these findings and highlight similarities between the regulation of cell death triggered by Cd and fumonisin B1. We consider how both compounds could be useful tools in dissecting plant cell death signaling. PMID:24398567

  1. Cell death sensitization of leukemia cells by opioid receptor activation

    PubMed Central

    Friesen, Claudia; Roscher, Mareike; Hormann, Inis; Fichtner, Iduna; Alt, Andreas; Hilger, Ralf A.; Debatin, Klaus-Michael; Miltner, Erich

    2013-01-01

    Cyclic AMP (cAMP) regulates a number of cellular processes and modulates cell death induction. cAMP levels are altered upon stimulation of specific G-protein-coupled receptors inhibiting or activating adenylyl cyclases. Opioid receptor stimulation can activate inhibitory Gi-proteins which in turn block adenylyl cyclase activity reducing cAMP. Opioids such as D,L-methadone induce cell death in leukemia cells. However, the mechanism how opioids trigger apoptosis and activate caspases in leukemia cells is not understood. In this study, we demonstrate that downregulation of cAMP induced by opioid receptor activation using the opioid D,L-methadone kills and sensitizes leukemia cells for doxorubicin treatment. Enhancing cAMP levels by blocking opioid-receptor signaling strongly reduced D,L-methadone-induced apoptosis, caspase activation and doxorubicin-sensitivity. Induction of cell death in leukemia cells by activation of opioid receptors using the opioid D,L-methadone depends on critical levels of opioid receptor expression on the cell surface. Doxorubicin increased opioid receptor expression in leukemia cells. In addition, the opioid D,L-methadone increased doxorubicin uptake and decreased doxorubicin efflux in leukemia cells, suggesting that the opioid D,L-methadone as well as doxorubicin mutually increase their cytotoxic potential. Furthermore, we found that opioid receptor activation using D,L-methadone alone or in addition to doxorubicin inhibits tumor growth significantly in vivo. These results demonstrate that opioid receptor activation via triggering the downregulation of cAMP induces apoptosis, activates caspases and sensitizes leukemia cells for doxorubicin treatment. Hence, opioid receptor activation seems to be a promising strategy to improve anticancer therapies. PMID:23633472

  2. Arabidopsis ACCELERATED CELL DEATH2 Modulates Programmed Cell DeathW⃞

    PubMed Central

    Yao, Nan; Greenberg, Jean T.

    2006-01-01

    The Arabidopsis thaliana chloroplast protein ACCELERATED CELL DEATH2 (ACD2) modulates the amount of programmed cell death (PCD) triggered by Pseudomonas syringae and protoporphyrin IX (PPIX) treatment. In vitro, ACD2 can reduce red chlorophyll catabolite, a chlorophyll derivative. We find that ACD2 shields root protoplasts that lack chlorophyll from light- and PPIX-induced PCD. Thus, chlorophyll catabolism is not obligatory for ACD2 anti-PCD function. Upon P. syringae infection, ACD2 levels and localization change in cells undergoing PCD and in their close neighbors. Thus, ACD2 shifts from being largely in chloroplasts to partitioning to chloroplasts, mitochondria, and, to a small extent, cytosol. ACD2 protects cells from PCD that requires the early mitochondrial oxidative burst. Later, the chloroplasts of dying cells generate NO, which only slightly affects cell viability. Finally, the mitochondria in dying cells have dramatically altered movements and cellular distribution. Overproduction of both ACD2 (localized to mitochondria and chloroplasts) and ascorbate peroxidase (localized to chloroplasts) greatly reduces P. syringae–induced PCD, suggesting a pro-PCD role for mitochondrial and chloroplast events. During infection, ACD2 may bind to and/or reduce PCD-inducing porphyrin-related molecules in mitochondria and possibly chloroplasts that generate reactive oxygen species, cause altered organelle behavior, and activate a cascade of PCD-inducing events. PMID:16387834

  3. Programmed cell death for defense against anomaly and tumor formation

    SciTech Connect

    Kondo, Sohei; Norimura, Toshiyuki; Nomura, Taisei

    1995-12-31

    Cell death after exposure to low-level radiation is often considered evidence that radiation is poisonous, however small the dose. Evidence has been accumulating to support the notion that cell death after low-level exposure to radiation results from activation of suicidal genes {open_quote}programmed cell death{close_quote} or {open_quote}apoptosis{close_quote} - for the health of the whole body. This paper gives experimental evidence that embryos of fruit flies and mouse fetuses have potent defense mechanisms against teratogenic or tumorigenic injury caused by radiation and carcinogens, which function through programmed cell death.

  4. Hydrogen peroxide as a signal controlling plant programmed cell death

    PubMed Central

    Gechev, Tsanko S.; Hille, Jacques

    2005-01-01

    Hydrogen peroxide (H2O2) has established itself as a key player in stress and programmed cell death responses, but little is known about the signaling pathways leading from H2O2 to programmed cell death in plants. Recently, identification of key regulatory mutants and near-full genome coverage microarray analysis of H2O2-induced cell death have begun to unravel the complexity of the H2O2 network. This review also describes a novel link between H2O2 and sphingolipids, two signals that can interplay and regulate plant cell death. PMID:15631987

  5. Death of mitochondria during programmed cell death of leaf mesophyll cells.

    PubMed

    Selga, Tūrs; Selga, Maija; Pāvila, Vineta

    2005-12-01

    The role of plant mitochondria in the programmed cell death (PCD) is widely discussed. However, spectrum and sequence of mitochondrial structural changes during different types of PCD in leaves are poorly described. Pea, cucumber and rye plants were grown under controlled growing conditions. A part of them were sprinkled with ethylene releaser to accelerate cell death. During yellowing the palisade parenchyma mitochondria were attracted to nuclear envelope. Mitochondrial matrix became electron translucent. Mitochondria entered vacuole by invagination of tonoplast and formed multivesicular bodies. Ethephon treatment increased the frequency of sticking of mitochondria to the nuclear envelope or chloroplasts and peroxisomes. Mitochondria divided by different mechanisms and became enclosed in Golgi and ER derived authopagic vacuoles or in the central vacuole. Several fold increase of the diameter of cristae became typical. In all cases mitochondria were attached to nuclear envelope. It can be considered as structural mechanism of promoting of PCD.

  6. α-Synuclein and neuronal cell death

    PubMed Central

    Cookson, Mark R

    2009-01-01

    α-Synuclein is a small protein that has special relevance for understanding Parkinson disease and related disorders. Not only is α-synuclein found in Lewy bodies characteristic of Parkinson disease, but also mutations in the gene for α-synuclein can cause an inherited form of Parkinson disease and expression of normal α-synuclein can increase the risk of developing Parkinson disease in sporadic, or non-familial, cases. Both sporadic and familial Parkinson disease are characterized by substantial loss of several groups of neurons, including the dopaminergic cells of the substantia nigra that are the target of most current symptomatic therapies. Therefore, it is predicted that α-synuclein, especially in its mutant forms or under conditions where its expression levels are increased, is a toxic protein in the sense that it is associated with an increased rate of neuronal cell death. This review will discuss the experimental contexts in which α-synuclein has been demonstrated to be toxic. I will also outline what is known about the mechanisms by which α-synuclein triggers neuronal damage, and identify some of the current gaps in our knowledge about this subject. Finally, the therapeutic implications of toxicity of α-synuclein will be discussed. PMID:19193223

  7. Photoreceptor cell death and rescue in retinal detachment and degenerations

    PubMed Central

    Murakami, Yusuke; Notomi, Shoji; Hisatomi, Toshio; Nakazawa, Toru; Ishibashi, Tatsuro; Miller, Joan W.; Vavvas, Demetrios G.

    2013-01-01

    Photoreceptor cell death is the ultimate cause of vision loss in various retinal disorders, including retinal detachment (RD). Photoreceptor cell death has been thought to occur mainly through apoptosis, which is the most characterized form of programmed cell death. The caspase family of cysteine proteases plays a central role for inducing apoptosis, and in experimental models of RD, dying photoreceptor cells exhibit caspase activation; however, there is a paradox that caspase inhibition alone does not provide a sufficient protection against photoreceptor cell loss, suggesting that other mechanisms of cell death are involved. Recent accumulating evidence demonstrates that non-apoptotic forms of cell death, such as autophagy and necrosis, are also regulated by specific molecular machinery, such as those mediated by autophagy-related proteins and receptor-interacting protein kinases, respectively. Here we summarize the current knowledge of cell death signaling and its roles in photoreceptor cell death after RD and other retinal degenerative diseases. A body of studies indicate that not only apoptotic but also autophagic and necrotic signaling are involved in photoreceptor cell death, and that combined targeting of these pathways may be an effective neuroprotective strategy for retinal diseases associated with photoreceptor cell loss. PMID:23994436

  8. Modulation of programmed cell death by medicinal plants.

    PubMed

    Thatte, U; Bagadey, S; Dahanukar, S

    2000-02-01

    Programmed cell death (apoptosis), a form of cell death, described by Kerr and Wyllie some 20 years ago, has generated considerable interest in recent years. The mechanisms by which this mode of cell death (seen both in animal and plant cells), takes place have been examined in detail. Extracellular signals and intracellular events have been elaborated. Of interest to the clinician, is the concentrated effort to study pharmacological modulation of programmed cell death. The attempt to influence the natural phenomenon of programmed cell death stems from the fact that it is reduced (like in cancer) or increased (like in neurodegenerative diseases) in several clinical situations. Thus, chemicals that can modify programmed cell death are likely to be potentially useful drugs. From foxglove, which gave digitalis to the Pacific Yew from which came taxol, plants have been a source of research material for useful drugs. Recently, a variety of plant extracts have been investigated for their ability to influence the apoptotic process. This article discusses some of the interesting data. The ability of plants to influence programmed cell death in cancerous cells in an attempt to arrest their proliferation has been the topic of much research. Various cell-lines like HL60, human hepatocellular carcinoma cell line (KIM-1), a cholangiocarcinoma cell-line (KMC-1), B-cell hybridomas, U937 a monocytic cell-line, HeLa cells, human lymphoid leukemia (MOLT-4B) cells and K562 cells have been studied. The agents found to induce programmed cell death (measured either morphologically or flow cytometrically) included extracts of plants like mistletoe and Semicarpus anacardium. Isolated compounds like bryonolic acid (from Trichosanthes kirilowii var. Japonica, crocin (from saffron) and allicin (from Allium sativum) have also been found to induce programmed cell death and therefore arrest proliferation. Even Chinese herbal medicine "Sho-saiko-to" induces programmed cell death in selected

  9. Bacterial programmed cell death of cerebral endothelial cells involves dual death pathways

    PubMed Central

    Bermpohl, Daniela; Halle, Annett; Freyer, Dorette; Dagand, Emilie; Braun, Johann S.; Bechmann, Ingo; Schröder, Nicolas W.J.; Weber, Joerg R.

    2005-01-01

    Major barriers separating the blood from tissue compartments in the body are composed of endothelial cells. Interaction of bacteria with such barriers defines the course of invasive infections, and meningitis has served as a model system to study endothelial cell injury. Here we report the impressive ability of Streptococcus pneumoniae, clinically one of the most important pathogens, to induce 2 morphologically distinct forms of programmed cell death (PCD) in brain-derived endothelial cells. Pneumococci and the major cytotoxins H202 and pneumolysin induce apoptosis-like PCD independent of TLR2 and TLR4. On the other hand, pneumococcal cell wall, a major proinflammatory component, causes caspase-driven classical apoptosis that is mediated through TLR2. These findings broaden the scope of bacterial-induced PCD, link these effects to innate immune TLRs, and provide insight into the acute and persistent phases of damage during meningitis. PMID:15902310

  10. Cell death programs in Yersinia immunity and pathogenesis

    PubMed Central

    Philip, Naomi H.; Brodsky, Igor E.

    2012-01-01

    Cell death plays a central role in host-pathogen interactions, as it can eliminate the pathogen's replicative niche and provide pro-inflammatory signals necessary for an effective immune response; conversely, cell death can allow pathogens to eliminate immune cells and evade anti-microbial effector mechanisms. In response to developmental signals or cell-intrinsic stresses, the executioner caspases-3 and -7 mediate apoptotic cell death, which is generally viewed as immunologically silent or immunosuppressive. A proinflammatory form of cell death that requires caspase-1, termed pyroptosis, is activated in response to microbial products within the host cytosol or disruption of cellular membranes by microbial pathogens. Infection by the bacterial pathogen Yersinia has features of both apoptosis and pyroptosis. Cell death and caspase-1 processing in Yersinia-infected cells occur in response to inhibition of NF-κB and MAPK signaling by the Yersinia virulence factor YopJ. However, the molecular basis of YopJ-induced cell death, and the role of different death pathways in anti-Yersinia immune responses remain enigmatic. Here, we discuss the role that cell death may play in inducing specific pro-inflammatory signals that shape innate and adaptive immune responses against Yersinia infection. PMID:23226685

  11. Cell-in-Cell Death Is Not Restricted by Caspase-3 Deficiency in MCF-7 Cells

    PubMed Central

    Wang, Shan; He, Meifang; Li, Linmei; Liang, Zhihua; Zou, Zehong

    2016-01-01

    Purpose Cell-in-cell structures are created by one living cell entering another homotypic or heterotypic living cell, which usually leads to the death of the internalized cell, specifically through caspase-dependent cell death (emperitosis) or lysosome-dependent cell death (entosis). Although entosis has attracted great attention, its occurrence is controversial, because one cell line used in its study (MCF-7) is deficient in caspase-3. Methods We investigated this issue using MCF-7 and A431 cell lines, which often display cell-in-cell invasion, and have different levels of caspase-3 expression. Cell-in-cell death morphology, microstructures, and signaling pathways were compared in the two cell lines. Results Our results confirmed that MCF-7 cells are caspase-3 deficient with a partial deletion in the CASP-3 gene. These cells underwent cell death that lacked typical apoptotic properties after staurosporine treatment, whereas caspase-3-sufficient A431 cells displayed typical apoptosis. The presence of caspase-3 was related neither to the lysosome-dependent nor to the caspase-dependent cell-in-cell death pathway. However, the existence of caspase-3 was associated with a switch from lysosome-dependent cell-in-cell death to the apoptotic cell-in-cell death pathway during entosis. Moreover, cellular hypoxia, mitochondrial swelling, release of cytochrome C, and autophagy were observed in internalized cells during entosis. Conclusion The occurrence of caspase-independent entosis is not a cell-specific process. In addition, entosis actually represents a cellular self-repair system, functioning through autophagy, to degrade damaged mitochondria resulting from cellular hypoxia in cell-in-cell structures. However, sustained autophagy-associated signal activation, without reduction in cellular hypoxia, eventually leads to lysosome-dependent intracellular cell death. PMID:27721872

  12. Cell death by necrosis, a regulated way to go.

    PubMed

    Henriquez, Mauricio; Armisén, Ricardo; Stutzin, Andrés; Quest, Andrew F G

    2008-05-01

    Apoptosis is a programmed form of cell death with well-defined morphological traits that are often associated with activation of caspases. More recently evidence has become available demonstrating that upon caspase inhibition alternative programs of cell death are executed, including ones with features characteristic of necrosis. These findings have changed our view of necrosis as a passive and essentially accidental form of cell death to that of an active, regulated and controllable process. Also necrosis has now been observed in parallel with, rather than as an alternative pathway to, apoptosis. Thus, cell death responses are extremely flexible despite being programmed. In this review, some of the hallmarks of different programmed cell death modes have been highlighted before focusing the discussion on necrosis. Obligatory events associated with this form of cell death include uncompensated cell swelling and related changes at the plasma membrane. In this context, representatives of the transient receptor channel family and their regulation are discussed. Also mechanisms that lead to execution of the necrotic cell death program are highlighted. Emphasis is laid on summarizing our understanding of events that permit switching between cell death modes and how they connect to necrosis. Finally, potential implications for the treatment of some disease states are mentioned. PMID:18473819

  13. Actin as Deathly Switch? How Auxin Can Suppress Cell-Death Related Defence

    PubMed Central

    Chang, Xiaoli; Riemann, Michael; Liu, Qiong; Nick, Peter

    2015-01-01

    Plant innate immunity is composed of two layers – a basal immunity, and a specific effector-triggered immunity, which is often accompanied by hypersensitive cell death. Initiation of cell death depends on a complex network of signalling pathways. The phytohormone auxin as central regulator of plant growth and development represents an important component for the modulation of plant defence. In our previous work, we showed that cell death is heralded by detachment of actin from the membrane. Both, actin response and cell death, are triggered by the bacterial elicitor harpin in grapevine cells. In this study we investigated, whether harpin-triggered actin bundling is necessary for harpin-triggered cell death. Since actin organisation is dependent upon auxin, we used different auxins to suppress actin bundling. Extracellular alkalinisation and transcription of defence genes as the basal immunity were examined as well as cell death. Furthermore, organisation of actin was observed in response to pharmacological manipulation of reactive oxygen species and phospholipase D. We find that induction of defence genes is independent of auxin. However, auxin can suppress harpin-induced cell death and also counteract actin bundling. We integrate our findings into a model, where harpin interferes with an auxin dependent pathway that sustains dynamic cortical actin through the activity of phospholipase D. The antagonism between growth and defence is explained by mutual competition for signal molecules such as superoxide and phosphatidic acid. Perturbations of the auxin-actin pathway might be used to detect disturbed integrity of the plasma membrane and channel defence signalling towards programmed cell death. PMID:25933033

  14. Triggering Death of Adherent Cells with Ultraviolet Radiation.

    PubMed

    Crowley, Lisa C; Waterhouse, Nigel J

    2016-01-01

    Ultraviolet (UV) radiation is a convenient stimulus for triggering cell death that is available in most laboratories. We use a Stratalinker UV cross-linker because it is a safe, cheap, reliable, consistent, and easily controlled source of UV irradiation. This protocol describes using a Stratalinker to trigger UV-induced death of HeLa cells. PMID:27371593

  15. Increased Mitochondrial Activity in Anthrax-Induced Cell Death

    PubMed Central

    Li, Chi

    2009-01-01

    Pathogenesis of anthrax lethal toxin (LT) is attributed to its ability to cause death of infected cells. New work has demonstrated that increase of mitochondrial F1F0 ATPase activity and subsequent depletion of cellular ATP level are critical early events during LT-induced cell death. PMID:26124679

  16. TRAIL restores DCA/metformin-mediated cell death in hypoxia.

    PubMed

    Hong, Sung-Eun; Kim, Chang Soon; An, Sungkwan; Kim, Hyun-Ah; Hwang, Sang-Gu; Song, Jie-Young; Lee, Jin Kyung; Hong, Jungil; Kim, Jong-Il; Noh, Woo Chul; Jin, Hyeon-Ok; Park, In-Chul

    2016-09-23

    Previous studies have shown that hypoxia can reverse DCA/metformin-induced cell death in breast cancer cells. Therefore, targeting hypoxia is necessary for therapies targeting cancer metabolism. In the present study, we found that TRAIL can overcome the effect of hypoxia on the cell death induced by treatment of DCA and metformin in breast cancer cells. Unexpectedly, DR5 is upregulated in the cells treated with DCA/metformin, and sustained under hypoxia. Blocking DR5 by siRNA inhibited DCA/metformin/TRAIL-induced cell death, indicating that DR5 upregulation plays an important role in sensitizing cancer cells to TRAIL-induced cell death. Furthermore, we found that activation of JNK and c-Jun is responsible for upregulation of DR5 induced by DCA/metformin. These findings support the potential application of combining TRAIL and metabolism-targeting drugs in the treatment of cancers under hypoxia. PMID:27569287

  17. The convergence of radiation and immunogenic cell death signaling pathways

    PubMed Central

    Golden, Encouse B.; Pellicciotta, Ilenia; Demaria, Sandra; Barcellos-Hoff, Mary H.; Formenti, Silvia C.

    2012-01-01

    Ionizing radiation (IR) triggers programmed cell death in tumor cells through a variety of highly regulated processes. Radiation-induced tumor cell death has been studied extensively in vitro and is widely attributed to multiple distinct mechanisms, including apoptosis, necrosis, mitotic catastrophe (MC), autophagy, and senescence, which may occur concurrently. When considering tumor cell death in the context of an organism, an emerging body of evidence suggests there is a reciprocal relationship in which radiation stimulates the immune system, which in turn contributes to tumor cell kill. As a result, traditional measurements of radiation-induced tumor cell death, in vitro, fail to represent the extent of clinically observed responses, including reductions in loco-regional failure rates and improvements in metastases free and overall survival. Hence, understanding the immunological responses to the type of radiation-induced cell death is critical. In this review, the mechanisms of radiation-induced tumor cell death are described, with particular focus on immunogenic cell death (ICD). Strategies combining radiotherapy with specific chemotherapies or immunotherapies capable of inducing a repertoire of cancer specific immunogens might potentiate tumor control not only by enhancing cell kill but also through the induction of a successful anti-tumor vaccination that improves patient survival. PMID:22891162

  18. Capsaicin induces immunogenic cell death in human osteosarcoma cells

    PubMed Central

    Jin, Tao; Wu, Hongyan; Wang, Yanlin; Peng, Hao

    2016-01-01

    Immunogenic cell death (ICD) is characterized by the early surface exposure of calreticulin (CRT). As a specific signaling molecule, CRT on the surface of apoptotic tumor cells mediates the recognition and phagocytosis of tumor cells by antigen presenting cells. To date, only a small quantity of anti-cancer chemicals have been found to induce ICD, therefore it is clinically important to identify novel chemicals that may induce ICD. The purpose of the present study is to explore the function of capsaicin in inducing ICD. In the current study, MTT assays were used to examine the growth inhibiting effects of MG-63 cells when they were treated with capsaicin or cisplatin. Mitochondrial membrane potential and western blot analysis were used to investigate capsaicin- and cisplatin-induced apoptosis. In addition, the effects of capsaicin and cisplatin were evaluated for their abilities in inducing calreticulin membrane translocation and mediating ICD in human osteosarcoma cells (MG-63). The results demonstrated that capsaicin and cisplatin can induce the apoptosis of MG-63 cells. However, only capsaicin induced a rapid translocation of CRT from the intracellular space to the cell surface. Treatment with capsaicin increased phagocytosis of MG-63 cells by dendritic cells (DCs), and these MG-63-loaded DCs could efficiently stimulate the secretion of IFN-γ by lymphocytes. These results identify capsaicin as an anti-cancer agent capable of inducing ICD in human osteosarcoma cells in vitro. PMID:27446273

  19. [Programmed cell death: history and future of a concept].

    PubMed

    Lockshin, Richard A

    2005-01-01

    Cell death was observed and understood since the 19th century, but there was no experimental examination until the mid-20th century. Beginning in the 1960's, several laboratories demonstrated that cell death was biologically controlled (programmed) and that the morphology was common and not readily explained (apoptosis). By 1990 the genetic basis of programmed cell death had been established and the first components of the cell death machinery (caspase 3, bcl-2 and Fas) had been identified, sequenced, and recognized as highly conserved in evolution. The rapid development of the field has given us substantial understanding of how cell death is achieved. However, capitalizing on our knowledge for therapeutic purposes requires us to learn much more about how a cell commits to death, as well as recognizing that apoptosis may be the most common and efficient means of death, but that there are alternative pathways that can result in cell death even when the conventional pathway is blocked. Interestingly enough, many of the arguments and missteps in the history of the field were anticipated by Claude Bernard, and his warnings and recommendations remain valid today.

  20. Nitric oxide and cell death in liver cancer cells.

    PubMed

    Muntané, Jordi; De la Rosa, Angel J; Marín, Luís M; Padillo, Francisco J

    2013-05-01

    Nitric oxide (NO) is a lipophillic, highly diffusible, and short-lived physiological messenger which regulates a variety of physiopathological responses. NO may exert its cellular action through cGMP-dependent and cGMP-independent pathways which includes different postranslational modifications. The effect of NO in cancer depends on the activity and localization of NOS isoforms, concentration and duration of NO exposure, cellular sensitivity, and hypoxia/re-oxygenation process. NO regulates critical factors such as the hypoxia inducible factor-1 (HIF-1) and p53 generally leading to growth arrest, apoptosis or adaptation. NO sensitizes hepatoma cells to chemotherapeutic compounds probably through increased p53 and cell death receptor expressions.

  1. Synchronized renal tubular cell death involves ferroptosis.

    PubMed

    Linkermann, Andreas; Skouta, Rachid; Himmerkus, Nina; Mulay, Shrikant R; Dewitz, Christin; De Zen, Federica; Prokai, Agnes; Zuchtriegel, Gabriele; Krombach, Fritz; Welz, Patrick-Simon; Weinlich, Ricardo; Vanden Berghe, Tom; Vandenabeele, Peter; Pasparakis, Manolis; Bleich, Markus; Weinberg, Joel M; Reichel, Christoph A; Bräsen, Jan Hinrich; Kunzendorf, Ulrich; Anders, Hans-Joachim; Stockwell, Brent R; Green, Douglas R; Krautwald, Stefan

    2014-11-25

    Receptor-interacting protein kinase 3 (RIPK3)-mediated necroptosis is thought to be the pathophysiologically predominant pathway that leads to regulated necrosis of parenchymal cells in ischemia-reperfusion injury (IRI), and loss of either Fas-associated protein with death domain (FADD) or caspase-8 is known to sensitize tissues to undergo spontaneous necroptosis. Here, we demonstrate that renal tubules do not undergo sensitization to necroptosis upon genetic ablation of either FADD or caspase-8 and that the RIPK1 inhibitor necrostatin-1 (Nec-1) does not protect freshly isolated tubules from hypoxic injury. In contrast, iron-dependent ferroptosis directly causes synchronized necrosis of renal tubules, as demonstrated by intravital microscopy in models of IRI and oxalate crystal-induced acute kidney injury. To suppress ferroptosis in vivo, we generated a novel third-generation ferrostatin (termed 16-86), which we demonstrate to be more stable, to metabolism and plasma, and more potent, compared with the first-in-class compound ferrostatin-1 (Fer-1). Even in conditions with extraordinarily severe IRI, 16-86 exerts strong protection to an extent which has not previously allowed survival in any murine setting. In addition, 16-86 further potentiates the strong protective effect on IRI mediated by combination therapy with necrostatins and compounds that inhibit mitochondrial permeability transition. Renal tubules thus represent a tissue that is not sensitized to necroptosis by loss of FADD or caspase-8. Finally, ferroptosis mediates postischemic and toxic renal necrosis, which may be therapeutically targeted by ferrostatins and by combination therapy. PMID:25385600

  2. Synchronized renal tubular cell death involves ferroptosis

    PubMed Central

    Skouta, Rachid; Himmerkus, Nina; Mulay, Shrikant R.; Dewitz, Christin; De Zen, Federica; Prokai, Agnes; Zuchtriegel, Gabriele; Krombach, Fritz; Welz, Patrick-Simon; Weinlich, Ricardo; Vanden Berghe, Tom; Vandenabeele, Peter; Pasparakis, Manolis; Bleich, Markus; Weinberg, Joel M.; Reichel, Christoph A.; Bräsen, Jan Hinrich; Kunzendorf, Ulrich; Anders, Hans-Joachim; Stockwell, Brent R.; Green, Douglas R.; Krautwald, Stefan

    2014-01-01

    Receptor-interacting protein kinase 3 (RIPK3)-mediated necroptosis is thought to be the pathophysiologically predominant pathway that leads to regulated necrosis of parenchymal cells in ischemia–reperfusion injury (IRI), and loss of either Fas-associated protein with death domain (FADD) or caspase-8 is known to sensitize tissues to undergo spontaneous necroptosis. Here, we demonstrate that renal tubules do not undergo sensitization to necroptosis upon genetic ablation of either FADD or caspase-8 and that the RIPK1 inhibitor necrostatin-1 (Nec-1) does not protect freshly isolated tubules from hypoxic injury. In contrast, iron-dependent ferroptosis directly causes synchronized necrosis of renal tubules, as demonstrated by intravital microscopy in models of IRI and oxalate crystal-induced acute kidney injury. To suppress ferroptosis in vivo, we generated a novel third-generation ferrostatin (termed 16-86), which we demonstrate to be more stable, to metabolism and plasma, and more potent, compared with the first-in-class compound ferrostatin-1 (Fer-1). Even in conditions with extraordinarily severe IRI, 16-86 exerts strong protection to an extent which has not previously allowed survival in any murine setting. In addition, 16-86 further potentiates the strong protective effect on IRI mediated by combination therapy with necrostatins and compounds that inhibit mitochondrial permeability transition. Renal tubules thus represent a tissue that is not sensitized to necroptosis by loss of FADD or caspase-8. Finally, ferroptosis mediates postischemic and toxic renal necrosis, which may be therapeutically targeted by ferrostatins and by combination therapy. PMID:25385600

  3. Independent controls for neocortical neuron production and histogenetic cell death

    NASA Technical Reports Server (NTRS)

    Verney, C.; Takahashi, T.; Bhide, P. G.; Nowakowski, R. S.; Caviness, V. S. Jr

    2000-01-01

    We estimated the proportion of cells eliminated by histogenetic cell death during the first 2 postnatal weeks in areas 1, 3 and 40 of the mouse parietal neocortex. For each layer and for the subcortical white matter in each neocortical area, the number of dying cells per mm(2) was calculated and the proportionate cell death for each day of the 2-week interval was estimated. The data show that cell death proceeds essentially uniformly across the neocortical areas and layers and that it does not follow either the spatiotemporal gradient of cell cycle progression in the pseudostratified ventricular epithelium of the cerebral wall, the source of neocortical neurons, or the 'inside-out' neocortical neuronogenetic sequence. Therefore, we infer that the control mechanisms of neocortical histogenetic cell death are independent of mechanisms controlling neuronogenesis or neuronal migration but may be associated with the ingrowth, expansion and a system-wide matching of neuronal connectivity. Copyright 2000 S. Karger AG, Basel.

  4. Programmed Cell Death and Complexity in Microbial Systems.

    PubMed

    Durand, Pierre M; Sym, Stuart; Michod, Richard E

    2016-07-11

    Programmed cell death (PCD) is central to organism development and for a long time was considered a hallmark of multicellularity. Its discovery, therefore, in unicellular organisms presents compelling questions. Why did PCD evolve? What is its ecological effect on communities? To answer these questions, one is compelled to consider the impacts of PCD beyond the cell, for death obviously lowers the fitness of the cell. Here, we examine the ecological effects of PCD in different microbial scenarios and conclude that PCD can increase biological complexity. In mixed microbial communities, the mode of death affects the microenvironment, impacting the interactions between taxa. Where the population comprises groups of relatives, death has a more explicit effect. Death by lysis or other means can be harmful, while PCD can evolve by providing advantages to relatives. The synchronization of death between individuals suggests a group level property is being maintained and the mode of death also appears to have had an impact during the origin of multicellularity. PCD can result in the export of fitness from the cell to the group level via re-usable resources and PCD may also provide a mechanism for how groups beget new groups comprising kin. Furthermore, PCD is a means for solving a central problem of group living - the toxic effects of death - by making resources in dying cells beneficial to others. What emerges from the data reviewed here is that while PCD carries an obvious cost to the cell, it can be a driver of complexity in microbial communities. PMID:27404254

  5. Sorafenib-induced defective autophagy promotes cell death by necroptosis.

    PubMed

    Kharaziha, Pedram; Chioureas, Dimitris; Baltatzis, George; Fonseca, Pedro; Rodriguez, Patricia; Gogvadze, Vladimir; Lennartsson, Lena; Björklund, Ann-Charlotte; Zhivotovsky, Boris; Grandér, Dan; Egevad, Lars; Nilsson, Sten; Panaretakis, Theocharis

    2015-11-10

    Autophagy is one of the main cytoprotective mechanisms that cancer cells deploy to withstand the cytotoxic stress and survive the lethal damage induced by anti-cancer drugs. However, under specific conditions, autophagy may, directly or indirectly, induce cell death. In our study, treatment of the Atg5-deficient DU145 prostate cancer cells, with the multi-tyrosine kinase inhibitor, sorafenib, induces mitochondrial damage, autophagy and cell death. Molecular inhibition of autophagy by silencing ULK1 and Beclin1 rescues DU145 cells from cell death indicating that, in this setting, autophagy promotes cell death. Re-expression of Atg5 restores the lipidation of LC3 and rescues DU145 and MEF atg5-/- cells from sorafenib-induced cell death. Despite the lack of Atg5 expression and LC3 lipidation, DU145 cells form autophagosomes as demonstrated by transmission and immuno-electron microscopy, and the formation of LC3 positive foci. However, the lack of cellular content in the autophagosomes, the accumulation of long-lived proteins, the presence of GFP-RFP-LC3 positive foci and the accumulated p62 protein levels indicate that these autophagosomes may not be fully functional. DU145 cells treated with sorafenib undergo a caspase-independent cell death that is inhibited by the RIPK1 inhibitor, necrostatin-1. Furthermore, treatment with sorafenib induces the interaction of RIPK1 with p62, as demonstrated by immunoprecipitation and a proximity ligation assay. Silencing of p62 decreases the RIPK1 protein levels and renders necrostatin-1 ineffective in blocking sorafenib-induced cell death. In summary, the formation of Atg5-deficient autophagosomes in response to sorafenib promotes the interaction of p62 with RIPK leading to cell death by necroptosis. PMID:26416459

  6. Sorafenib-induced defective autophagy promotes cell death by necroptosis

    PubMed Central

    Kharaziha, Pedram; Chioureas, Dimitris; Baltatzis, George; Fonseca, Pedro; Rodriguez, Patricia; Gogvadze, Vladimir; Lennartsson, Lena; Björklund, Ann-Charlotte; Zhivotovsky, Boris; Grandér, Dan; Egevad, Lars; Nilsson, Sten; Panaretakis, Theocharis

    2015-01-01

    Autophagy is one of the main cytoprotective mechanisms that cancer cells deploy to withstand the cytotoxic stress and survive the lethal damage induced by anti-cancer drugs. However, under specific conditions, autophagy may, directly or indirectly, induce cell death. In our study, treatment of the Atg5-deficient DU145 prostate cancer cells, with the multi-tyrosine kinase inhibitor, sorafenib, induces mitochondrial damage, autophagy and cell death. Molecular inhibition of autophagy by silencing ULK1 and Beclin1 rescues DU145 cells from cell death indicating that, in this setting, autophagy promotes cell death. Re-expression of Atg5 restores the lipidation of LC3 and rescues DU145 and MEF atg5−/− cells from sorafenib-induced cell death. Despite the lack of Atg5 expression and LC3 lipidation, DU145 cells form autophagosomes as demonstrated by transmission and immuno-electron microscopy, and the formation of LC3 positive foci. However, the lack of cellular content in the autophagosomes, the accumulation of long-lived proteins, the presence of GFP-RFP-LC3 positive foci and the accumulated p62 protein levels indicate that these autophagosomes may not be fully functional. DU145 cells treated with sorafenib undergo a caspase-independent cell death that is inhibited by the RIPK1 inhibitor, necrostatin-1. Furthermore, treatment with sorafenib induces the interaction of RIPK1 with p62, as demonstrated by immunoprecipitation and a proximity ligation assay. Silencing of p62 decreases the RIPK1 protein levels and renders necrostatin-1 ineffective in blocking sorafenib-induced cell death. In summary, the formation of Atg5-deficient autophagosomes in response to sorafenib promotes the interaction of p62 with RIPK leading to cell death by necroptosis. PMID:26416459

  7. Stem cell death and survival in heart regeneration and repair.

    PubMed

    Abdelwahid, Eltyeb; Kalvelyte, Audrone; Stulpinas, Aurimas; de Carvalho, Katherine Athayde Teixeira; Guarita-Souza, Luiz Cesar; Foldes, Gabor

    2016-03-01

    Cardiovascular diseases are major causes of mortality and morbidity. Cardiomyocyte apoptosis disrupts cardiac function and leads to cardiac decompensation and terminal heart failure. Delineating the regulatory signaling pathways that orchestrate cell survival in the heart has significant therapeutic implications. Cardiac tissue has limited capacity to regenerate and repair. Stem cell therapy is a successful approach for repairing and regenerating ischemic cardiac tissue; however, transplanted cells display very high death percentage, a problem that affects success of tissue regeneration. Stem cells display multipotency or pluripotency and undergo self-renewal, however these events are negatively influenced by upregulation of cell death machinery that induces the significant decrease in survival and differentiation signals upon cardiovascular injury. While efforts to identify cell types and molecular pathways that promote cardiac tissue regeneration have been productive, studies that focus on blocking the extensive cell death after transplantation are limited. The control of cell death includes multiple networks rather than one crucial pathway, which underlies the challenge of identifying the interaction between various cellular and biochemical components. This review is aimed at exploiting the molecular mechanisms by which stem cells resist death signals to develop into mature and healthy cardiac cells. Specifically, we focus on a number of factors that control death and survival of stem cells upon transplantation and ultimately affect cardiac regeneration. We also discuss potential survival enhancing strategies and how they could be meaningful in the design of targeted therapies that improve cardiac function.

  8. Noncanonical cell death in the nematode Caenorhabditis elegans

    PubMed Central

    Kinet, Maxime J.; Shaham, Shai

    2014-01-01

    The nematode Caenorhabditis. elegans has served as a fruitful setting for cell death research for over three decades. A conserved pathway of four genes, egl-1/BH3-only, ced-9/Bcl-2, ced-4/Apaf-1, and ced-3/caspase, coordinates most developmental cell deaths in C. elegans. However, other cell death forms, programmed and pathological, have also been described in this animal. Some of these share morphological and/or molecular similarities with the canonical apoptotic pathway, while others do not. Indeed, recent studies suggest the existence of an entirely novel mode of programmed developmental cell destruction that may also be conserved beyond nematodes. Here we review evidence for these noncanonical pathways. We propose that different cell death modalities can function as backup mechanisms for apoptosis, or as tailor-made programs that allow specific dying cells to be efficiently cleared from the animal. PMID:25065890

  9. Establishment of functional acinar-like cultures from human salivary glands.

    PubMed

    Jang, S I; Ong, H L; Gallo, A; Liu, X; Illei, G; Alevizos, I

    2015-02-01

    Disorders of human salivary glands resulting from therapeutic radiation treatment for head and neck cancers or from the autoimmune disease Sjögren syndrome (SS) frequently result in the reduction or complete loss of saliva secretion. Such irreversible dysfunction of the salivary glands is due to the impairment of acinar cells, the major glandular cells of protein, salt secretion, and fluid movement. Availability of primary epithelial cells from human salivary gland tissue is critical for studying the underlying mechanisms of these irreversible disorders. We applied 2 culture system techniques on human minor salivary gland epithelial cells (phmSG) and optimized the growth conditions to achieve the maintenance of phmSG in an acinar-like phenotype. These phmSG cells exhibited progenitor cell markers (keratin 5 and nanog) as well as acinar-specific markers-namely, α-amylase, cystatin C, TMEM16A, and NKCC1. Importantly, with an increase of the calcium concentration in the growth medium, these phmSG cells were further promoted to acinar-like cells in vitro, as indicated by an increase in AQP5 expression. In addition, these phmSG cells also demonstrated functional calcium mobilization, formation of epithelial monolayer with high transepithelial electrical resistance (TER), and polarized secretion of α-amylase secretion after β-adrenergic receptor stimulation. Taken together, suitable growth conditions have been established to isolate and support culture of acinar-like cells from the human salivary gland. These primary epithelial cells can be useful for study of molecular mechanisms involved in regulating the function of acinar cells and in the loss of salivary gland function in patients.

  10. A necrotic cell death model in a protist.

    PubMed

    Laporte, C; Kosta, A; Klein, G; Aubry, L; Lam, D; Tresse, E; Luciani, M F; Golstein, P

    2007-02-01

    While necrotic cell death is attracting considerable interest, its molecular bases are still poorly understood. Investigations in simple biological models, taken for instance outside the animal kingdom, may benefit from less interference from other cell death mechanisms and from better experimental accessibility, while providing phylogenetic information. Can necrotic cell death occur outside the animal kingdom? In the protist Dictyostelium, developmental stimuli induced in an autophagy mutant a stereotyped sequence of events characteristic of necrotic cell death. This sequence included swift mitochondrial uncoupling with mitochondrial 2',7'-dichlorofluorescein diacetate fluorescence, ATP depletion and increased oxygen consumption. This was followed by perinuclear clustering of dilated mitochondria. Rapid plasma membrane rupture then occurred, which was evidenced by time-lapse videos and quantified by FACS. Of additional interest, developmental stimuli and classical mitochondrial uncouplers triggered a similar sequence of events, and exogenous glucose delayed plasma membrane rupture in a nonglycolytic manner. The occurrence of necrotic cell death in the protist Dictyostelium (1) provides a very favorable model for further study of this type of cell death, and (2) strongly suggests that the mechanism underlying necrotic cell death was present in an ancestor common to the Amoebozoa protists and to animals and has been conserved in evolution.

  11. Slug inhibits pancreatic cancer initiation by blocking Kras-induced acinar-ductal metaplasia

    PubMed Central

    Ebine, Kazumi; Chow, Christina R.; DeCant, Brian T.; Hattaway, Holly Z.; Grippo, Paul J.; Kumar, Krishan; Munshi, Hidayatullah G.

    2016-01-01

    Cells in the pancreas that have undergone acinar-ductal metaplasia (ADM) can transform into premalignant cells that can eventually become cancerous. Although the epithelial-mesenchymal transition regulator Snail (Snai1) can cooperate with Kras in acinar cells to enhance ADM development, the contribution of Snail-related protein Slug (Snai2) to ADM development is not known. Thus, transgenic mice expressing Slug and Kras in acinar cells were generated. Surprisingly, Slug attenuated Kras-induced ADM development, ERK1/2 phosphorylation and proliferation. Co-expression of Slug with Kras also attenuated chronic pancreatitis-induced changes in ADM development and fibrosis. In addition, Slug attenuated TGF-α-induced acinar cell metaplasia to ductal structures and TGF-α-induced expression of ductal markers in ex vivo acinar explant cultures. Significantly, blocking the Rho-associated protein kinase ROCK1/2 in the ex vivo cultures induced expression of ductal markers and reversed the effects of Slug by inducing ductal structures. In addition, blocking ROCK1/2 activity in Slug-expressing Kras mice reversed the inhibitory effects of Slug on ADM, ERK1/2 phosphorylation, proliferation and fibrosis. Overall, these results increase our understanding of the role of Slug in ADM, an early event that can eventually lead to pancreatic cancer development. PMID:27364947

  12. [Death].

    PubMed

    Ribas, Jordi Domingo

    2003-12-01

    Intercultural factors are essential for reflection. In this article, the authors deals with a more direct vision on the special edition about Grief and Mourning, about the topic which lies in the depths of all of our consciences: death and the question what lies beyond death? The author provides us elements to reflect about concepts, some accepted in various cases, rejected in others, but always polemical, which help us to penetrate farther into the real mystery of life: death and what follows death.

  13. Neuronal cell death in neonatal hypoxia-ischemia.

    PubMed

    Northington, Frances J; Chavez-Valdez, Raul; Martin, Lee J

    2011-05-01

    Perinatal hypoxic-ischemic encephalopathy (HIE) is a significant cause of mortality and morbidity in infants and young children. Therapeutic opportunities are very limited for neonatal and pediatric HIE. Specific neural systems and populations of cells are selectively vulnerable in HIE; however, the mechanisms of degeneration are unresolved. These mechanisms involve oxidative stress, excitotoxicity, inflammation, and the activation of several different cell death pathways. Decades ago the structural and mechanistic basis of the cellular degeneration in HIE was thought to be necrosis. Subsequently, largely due to advances in cell biology and to experimental animal studies, emphasis has been switched to apoptosis or autophagy mediated by programmed cell death (PCD) mechanisms as important forms of degeneration in HIE. We have conceptualized based on morphological and biochemical data that this degeneration is better classified according to an apoptosis-necrosis cell death continuum and that programmed cell necrosis has prominent contribution in the neurodegeneration of HIE in animal models. It is likely that neonatal HIE evolves through many cell death chreodes influenced by the dynamic injury landscape. The relevant injury mechanisms remain to be determined in human neonatal HIE, though preliminary work suggests a complexity in the cell death mechanisms greater than that anticipated from experimental animal models. The accurate identification of the various cell death chreodes and their mechanisms unfolding within the immature brain matrix could provide fresh insight for developing meaningful therapies for neonatal and pediatric HIE. PMID:21520238

  14. Ferroptosis is Involved in Acetaminophen Induced Cell Death.

    PubMed

    Lőrincz, Tamás; Jemnitz, Katalin; Kardon, Tamás; Mandl, József; Szarka, András

    2015-09-01

    The recently described form of programmed cell death, ferroptosis can be induced by agents causing GSH depletion or the inhibition of GPX4. Ferroptosis clearly shows distinct morphologic, biochemical and genetic features from apoptosis, necrosis and autophagy. Since NAPQI the highly reactive metabolite of the widely applied analgesic and antipyretic, acetaminophen induces a cell death which can be characterized by GSH depletion, GPX inhibition and caspase independency the involvement of ferroptosis in acetaminophen induced cell death has been investigated. The specific ferroptosis inhibitor ferrostatin-1 failed to elevate the viability of acetaminophen treated HepG2 cells. It should be noticed that these cells do not form NAPQI due to the lack of phase I enzyme expression therefore GSH depletion cannot be observed. However in the case of acetaminophen treated primary mouse hepatocytes the significant elevation of cell viability could be observed upon ferrostatin-1 treatment. Similar to ferrostatin-1 treatment, the addition of the RIP1 kinase inhibitor necrostatin-1 could also elevate the viability of acetaminophen treated primary hepatocytes. Ferrostatin-1 has no influence on the expression of CYP2E1 or on the cellular GSH level which suggest that the protective effect of ferrostatin-1 in APAP induced cell death is not based on the reduced metabolism of APAP to NAPQI or on altered NAPQI conjugation by cellular GSH. Our results suggest that beyond necroptosis and apoptosis a third programmed cell death, ferroptosis is also involved in acetaminophen induced cell death in primary hepatocytes.

  15. Neuronal Cell Death in Neonatal Hypoxia-Ischemia

    PubMed Central

    Northington, Frances J.; Chavez-Valdez, Raul; Martin, Lee J.

    2014-01-01

    Perinatal hypoxic-ischemic encephalopathy (HIE) is a significant cause of mortality and morbidity in infants and young children. Therapeutic opportunities are very limited for neonatal and pediatric HIE. Specific neural systems and populations of cells are selectively vulnerable in HIE; however, the mechanisms of degeneration are unresolved. These mechanisms involve oxidative stress, excitotoxicity, inflammation, and the activation of several different cell death pathways. Decades ago the structural and mechanistic basis of the cellular degeneration in HIE was thought to be necrosis. Subsequently, largely due to advances in cell biology and to experimental animal studies, emphasis has been switched to apoptosis or autophagy mediated by programmed cell death (PCD) mechanisms as important forms of degeneration in HIE. We have conceptualized based on morphological and biochemical data that this degeneration is better classified according to an apoptosis-necrosis cell death continuum and that programmed cell necrosis has prominent contribution in the neurodegeneration of HIE in animal models. It is likely that neonatal HIE evolves through many cell death chreodes influenced by the dynamic injury landscape. The relevant injury mechanisms remain to be determined in human neonatal HIE, though preliminary work suggests a complexity in the cell death mechanisms greater than that anticipated from experimental animal models. The accurate identification of the various cell death chreodes and their mechanisms unfolding within the immature brain matrix could provide fresh insight for developing meaningful therapies for neonatal and pediatric HIE. PMID:21520238

  16. Ferroptosis is Involved in Acetaminophen Induced Cell Death.

    PubMed

    Lőrincz, Tamás; Jemnitz, Katalin; Kardon, Tamás; Mandl, József; Szarka, András

    2015-09-01

    The recently described form of programmed cell death, ferroptosis can be induced by agents causing GSH depletion or the inhibition of GPX4. Ferroptosis clearly shows distinct morphologic, biochemical and genetic features from apoptosis, necrosis and autophagy. Since NAPQI the highly reactive metabolite of the widely applied analgesic and antipyretic, acetaminophen induces a cell death which can be characterized by GSH depletion, GPX inhibition and caspase independency the involvement of ferroptosis in acetaminophen induced cell death has been investigated. The specific ferroptosis inhibitor ferrostatin-1 failed to elevate the viability of acetaminophen treated HepG2 cells. It should be noticed that these cells do not form NAPQI due to the lack of phase I enzyme expression therefore GSH depletion cannot be observed. However in the case of acetaminophen treated primary mouse hepatocytes the significant elevation of cell viability could be observed upon ferrostatin-1 treatment. Similar to ferrostatin-1 treatment, the addition of the RIP1 kinase inhibitor necrostatin-1 could also elevate the viability of acetaminophen treated primary hepatocytes. Ferrostatin-1 has no influence on the expression of CYP2E1 or on the cellular GSH level which suggest that the protective effect of ferrostatin-1 in APAP induced cell death is not based on the reduced metabolism of APAP to NAPQI or on altered NAPQI conjugation by cellular GSH. Our results suggest that beyond necroptosis and apoptosis a third programmed cell death, ferroptosis is also involved in acetaminophen induced cell death in primary hepatocytes. PMID:25962350

  17. Sickle cell trait and sudden death--bringing it home.

    PubMed Central

    Mitchell, Bruce L.

    2007-01-01

    Sickle cell trait continues to be the leading cause of sudden death for young African Americans in military basic training and civilian organized sports. The syndrome may have caused the death of up to 10 college football players since 1974 and, as recently as 2000, was suspected as the cause of death of three U.S. Army recruits. The penal military-style boot camps in the United States and the recent death of two teenagers with sickle cell trait merits renewed vigor in the education of athletic instructors, the military and the public about conditions associated with sudden death in individuals with sickle cell trait. Images Figure 1 Figure 2 PMID:17393956

  18. Radiation-induced Cochlea hair cell death: mechanisms and protection.

    PubMed

    Tan, Pei-Xin; Du, Sha-Sha; Ren, Chen; Yao, Qi-Wei; Yuan, Ya-Wei

    2013-01-01

    Cochlea hair cell death is regarded to be responsible for the radiation-induced sensorineural hearing loss (SNHL), which is one of the principal complications of radiotherapy (RT) for head and neck cancers. In this mini- review, we focus on the current progresses trying to unravel mechanisms of radiation-induced hair cell death and find out possible protection. P53, reactive oxygen species (ROS) and c-Jun N-terminal kinase (JNK) pathways have been proposed as pivotal in the processes leading to radiation hair cell death. Potential protectants, such as amifostine, N-acetylcysteine (NAC) and epicatechin (EC) , are claimed to be effective at reducing radiation- inducedhair cell death. The RT dosage, selection and application of concurrent chemotherapy should be pre- examined in order to minimize the damage to cochlea hair cells.

  19. Octylphenol induces vitellogenin production and cell death in fish hepatocytes

    SciTech Connect

    Toomey, B.H.; Monteverdi, G.H.; Di Giulio, R.T.

    1999-04-01

    The effects of octylphenol (OP) on vitellogenin production and cell death in hepatocytes from brown bullhead catfish (Americurus nebulosus) were studied. Production of vitellogenin was induced in hepatocytes exposed to 10 to 50 {micro}M OP, whereas a higher concentration of OP (100 {micro}M) induced apoptotic cell death. By 3 h after the addition of 100 {micro}M OP, dying cells showed chromatin condensation and DNA fragmentation as determined by fluorescence microscopy and gel electrophoresis. Later stages of cell death (nuclear membrane breakdown and cell fragmentation into apoptotic bodies) were identified in cells exposed to OP for at least 6 h. Hepatocytes exposed to 100 {micro}M OP also produced less vitellogenin than cells exposed to 50 {micro}M OP. An estrogen receptor antagonist, tamoxifen, greatly decreased vitellogenin production in OP-exposed hepatocytes from male fish but did not decrease cell death in these cells. Thus, although the ability of OP to induce vitellogenin production is likely mediated through interactions with the estrogen receptor, the induction of apoptotic cell death by OP does not appear to be dependent on its estrogenic activity but may be a more general toxic effect.

  20. Cell biology: Death drags down the neighbourhood

    NASA Astrophysics Data System (ADS)

    Vasquez, Claudia G.; Martin, Adam C.

    2015-02-01

    An analysis of dying cells reveals that they play an active part in modifying tissue shape by pulling on neighbouring cells. This induces neighbouring cells to contract at their apices, which results in tissue folding. See Letter p.245

  1. The Impact of Autophagy on Cell Death Modalities

    PubMed Central

    Ryter, Stefan W.; Choi, Augustine M. K.

    2014-01-01

    Autophagy represents a homeostatic cellular mechanism for the turnover of organelles and proteins, through a lysosome-dependent degradation pathway. During starvation, autophagy facilitates cell survival through the recycling of metabolic precursors. Additionally, autophagy can modulate other vital processes such as programmed cell death (e.g., apoptosis), inflammation, and adaptive immune mechanisms and thereby influence disease pathogenesis. Selective pathways can target distinct cargoes (e.g., mitochondria and proteins) for autophagic degradation. At present, the causal relationship between autophagy and various forms of regulated or nonregulated cell death remains unclear. Autophagy can occur in association with necrosis-like cell death triggered by caspase inhibition. Autophagy and apoptosis have been shown to be coincident or antagonistic, depending on experimental context, and share cross-talk between signal transduction elements. Autophagy may modulate the outcome of other regulated forms of cell death such as necroptosis. Recent advances suggest that autophagy can dampen inflammatory responses, including inflammasome-dependent caspase-1 activation and maturation of proinflammatory cytokines. Autophagy may also act as regulator of caspase-1 dependent cell death (pyroptosis). Strategies aimed at modulating autophagy may lead to therapeutic interventions for diseases in which apoptosis or other forms of regulated cell death may play a cardinal role. PMID:24639873

  2. Heme oxygenase-1 accelerates erastin-induced ferroptotic cell death

    PubMed Central

    Kwon, Min-Young; Park, Eunhee

    2015-01-01

    The oncogenic RAS-selective lethal small molecule Erastin triggers a unique iron-dependent form of nonapoptotic cell death termed ferroptosis. Ferroptosis is dependent upon the production of intracellular iron-dependent reactive oxygen species (ROS), but not other metals. However, key regulators remain unknown. The heme oxygenase (HO) is a major intracellular source of iron. In this study, the role of heme oxygenase in Erastin-triggered ferroptotic cancer cell death has been investigated. Zinc protoporphyrin IX (ZnPP), a HO-1 inhibitor, prevented Erastin-triggered ferroptotic cancer cell death. Furthermore, Erastin induced the protein and mRNA levels of HO-1 in HT-1080 fibrosarcoma cells. HO-1+/+ and HO-1−/− fibroblast, HO-1 overexpression, and chycloheximide-treated experiments revealed that the expression of HO-1 has a decisive effects in Erastin-triggered cell death. Hemin and CO-releasing molecules (CORM) promote Erastin-induced ferroptotic cell death, not by biliverdin and bilirubin. In addition, hemin and CORM accelerate the HO-1 expression in the presence of Erastin and increase membranous lipid peroxidation. Thus, HO-1 is an essential enzyme for iron-dependent lipid peroxidation during ferroptotic cell death. PMID:26405158

  3. Inhibition of regulated cell death by cell-penetrating peptides.

    PubMed

    Krautwald, Stefan; Dewitz, Christin; Fändrich, Fred; Kunzendorf, Ulrich

    2016-06-01

    Development of the means to efficiently and continuously renew missing and non-functional proteins in diseased cells remains a major goal in modern molecular medicine. While gene therapy has the potential to achieve this, substantial obstacles must be overcome before clinical application can be considered. A promising alternative approach is the direct delivery of non-permeant active biomolecules, such as oligonucleotides, peptides and proteins, to the affected cells with the purpose of ameliorating an advanced disease process. In addition to receptor-mediated endocytosis, cell-penetrating peptides are widely used as vectors for rapid translocation of conjugated molecules across cell membranes into intracellular compartments and the delivery of these therapeutic molecules is generally referred to as novel prospective protein therapy. As a broad coverage of the enormous amount of published data in this field is unrewarding, this review will provide a brief, focused overview of the technology and a summary of recent studies of the most commonly used protein transduction domains and their potential as therapeutic agents for the treatment of cellular damage and the prevention of regulated cell death. PMID:27048815

  4. Acetylsalicylic acid induces programmed cell death in Arabidopsis cell cultures.

    PubMed

    García-Heredia, José M; Hervás, Manuel; De la Rosa, Miguel A; Navarro, José A

    2008-06-01

    Acetylsalicylic acid (ASA), a derivative from the plant hormone salicylic acid (SA), is a commonly used drug that has a dual role in animal organisms as an anti-inflammatory and anticancer agent. It acts as an inhibitor of cyclooxygenases (COXs), which catalyze prostaglandins production. It is known that ASA serves as an apoptotic agent on cancer cells through the inhibition of the COX-2 enzyme. Here, we provide evidences that ASA also behaves as an agent inducing programmed cell death (PCD) in cell cultures of the model plant Arabidopsis thaliana, in a similar way than the well-established PCD-inducing agent H(2)O(2), although the induction of PCD by ASA requires much lower inducer concentrations. Moreover, ASA is herein shown to be a more efficient PCD-inducing agent than salicylic acid. ASA treatment of Arabidopsis cells induces typical PCD-linked morphological and biochemical changes, namely cell shrinkage, nuclear DNA degradation, loss of mitochondrial membrane potential, cytochrome c release from mitochondria and induction of caspase-like activity. However, the ASA effect can be partially reverted by jasmonic acid. Taking together, these results reveal the existence of common features in ASA-induced animal apoptosis and plant PCD, and also suggest that there are similarities between the pathways of synthesis and function of prostanoid-like lipid mediators in animal and plant organisms.

  5. Targeting Cell Death Pathways for Therapeutic Intervention in Kidney Diseases.

    PubMed

    Garg, Jay P; Vucic, Domagoj

    2016-05-01

    Precise regulation of cell death and survival is essential for proper maintenance of organismal homeostasis, development, and the immune system. Deregulated cell death can lead to developmental defects, neuropathies, infections, and cancer. Kidney diseases, especially acute pathologies linked to ischemia-reperfusion injury, are among illnesses that profoundly are affected by improper regulation or execution of cell death pathways. Attempts to develop medicines for kidney diseases have been impacted by the complexity of these pathologies given the heterogeneous patient population and diverse etiologies. By analyzing cell death pathways activated in kidney diseases, we attempt to differentiate their importance for these pathologies with a goal of identifying those that have more profound impact and the best therapeutic potential. Although classic apoptosis still might be important, regulated necrosis pathways including necroptosis, ferroptosis, parthanatos, and mitochondrial permeability transition-associated cell death play a significantly role in kidney diseases, especially in acute kidney pathologies. Although targeting receptor-interacting protein 1 kinase appears to be the best therapeutic strategy, combination with inhibitors of other cell death pathways is likely to bring superior benefit and possible cure to patients suffering from kidney diseases. PMID:27339381

  6. Prodigiosin inhibits motility and activates bacterial cell death revealing molecular biomarkers of programmed cell death.

    PubMed

    Darshan, N; Manonmani, H K

    2016-12-01

    The antimicrobial activity of prodigiosin from Serratia nematodiphila darsh1, a bacterial pigment was tested against few food borne bacterial pathogens Bacillus cereus, Staphylococcus aureus, Pseudomonas aeruginosa and Escherichia coli. The mode of action of prodigiosin was studied. Prodigiosin induced bactericidal activity indicating a stereotypical set of biochemical and morphological feature of Programmed cell death (PCD). PCD involves DNA fragmentation, generation of ROS, and expression of a protein with caspase-like substrate specificity in bacterial cells. Prodigiosin was observed to be internalized into bacterial cells and was localized predominantly in the membrane and the nuclear fraction, thus, facilitating intracellular trafficking and then binding of prodigiosin to the bacterial DNA. Corresponding to an increasing concentration of prodigiosin, the level of certain proteases were observed to increase in bacteria studied, thus initiating the onset of PCD. Prodigiosin at a sub-inhibitory concentration inhibits motility of pathogens. Our observations indicated that prodigiosin could be a promising antibacterial agent and could be used in the prevention of bacterial infections. PMID:27460563

  7. Prodigiosin inhibits motility and activates bacterial cell death revealing molecular biomarkers of programmed cell death.

    PubMed

    Darshan, N; Manonmani, H K

    2016-12-01

    The antimicrobial activity of prodigiosin from Serratia nematodiphila darsh1, a bacterial pigment was tested against few food borne bacterial pathogens Bacillus cereus, Staphylococcus aureus, Pseudomonas aeruginosa and Escherichia coli. The mode of action of prodigiosin was studied. Prodigiosin induced bactericidal activity indicating a stereotypical set of biochemical and morphological feature of Programmed cell death (PCD). PCD involves DNA fragmentation, generation of ROS, and expression of a protein with caspase-like substrate specificity in bacterial cells. Prodigiosin was observed to be internalized into bacterial cells and was localized predominantly in the membrane and the nuclear fraction, thus, facilitating intracellular trafficking and then binding of prodigiosin to the bacterial DNA. Corresponding to an increasing concentration of prodigiosin, the level of certain proteases were observed to increase in bacteria studied, thus initiating the onset of PCD. Prodigiosin at a sub-inhibitory concentration inhibits motility of pathogens. Our observations indicated that prodigiosin could be a promising antibacterial agent and could be used in the prevention of bacterial infections.

  8. Cell death during crisis is mediated by mitotic telomere deprotection.

    PubMed

    Hayashi, Makoto T; Cesare, Anthony J; Rivera, Teresa; Karlseder, Jan

    2015-06-25

    Tumour formation is blocked by two barriers: replicative senescence and crisis. Senescence is triggered by short telomeres and is bypassed by disruption of tumour-suppressive pathways. After senescence bypass, cells undergo crisis, during which almost all of the cells in the population die. Cells that escape crisis harbour unstable genomes and other parameters of transformation. The mechanism of cell death during crisis remains unexplained. Here we show that human cells in crisis undergo spontaneous mitotic arrest, resulting in death during mitosis or in the following cell cycle. This phenotype is induced by loss of p53 function, and is suppressed by telomerase overexpression. Telomere fusions triggered mitotic arrest in p53-compromised non-crisis cells, indicating that such fusions are the underlying cause of cell death. Exacerbation of mitotic telomere deprotection by partial TRF2 (also known as TERF2) knockdown increased the ratio of cells that died during mitotic arrest and sensitized cancer cells to mitotic poisons. We propose a crisis pathway wherein chromosome fusions induce mitotic arrest, resulting in mitotic telomere deprotection and cell death, thereby eliminating precancerous cells from the population.

  9. Surviving apoptosis: life-death signaling in single cells

    PubMed Central

    Flusberg, Deborah A.; Sorger, Peter K.

    2015-01-01

    Tissue development and homeostasis are regulated by opposing pro-survival and pro-death signals. An interesting feature of the Tumor Necrosis Factor (TNF) family of ligands is that they simultaneously activate opposing signals within a single cell via the same ligand-receptor complex. The magnitude of pro-death events such as caspase activation and pro-survival events such as NF-κB activation vary not only from one cell type to the next but also among individual cells of the same type due to intrinsic and extrinsic noise. The molecules involved in these pro-survival/pro-death pathways, and the different phenotypes that result from their activities, have been recently reviewed. Here we focus on the impact of cell-to-cell variability in the strength of these opposing signals on shaping cell fate decisions. PMID:25920803

  10. Centrality of host cell death in plant-microbe interactions.

    PubMed

    Dickman, Martin B; Fluhr, Robert

    2013-01-01

    Programmed cell death (PCD) is essential for proper growth, development, and cellular homeostasis in all eukaryotes. The regulation of PCD is of central importance in plant-microbe interactions; notably, PCD and features associated with PCD are observed in many host resistance responses. Conversely, pathogen induction of inappropriate cell death in the host results in a susceptible phenotype and disease. Thus, the party in control of PCD has a distinct advantage in these battles. PCD processes appear to be of ancient origin, as indicated by the fact that many features of cell death strategy are conserved between animals and plants; however, some of the details of death execution differ. Mammalian core PCD genes, such as caspases, are not present in plant genomes. Similarly, pro- and antiapoptotic mammalian regulatory elements are absent in plants, but, remarkably, when expressed in plants, successfully impact plant PCD. Thus, subtle structural similarities independent of sequence homology appear to sustain operational equivalence. The vacuole is emerging as a key organelle in the modulation of plant PCD. Under different signals for cell death, the vacuole either fuses with the plasmalemma membrane or disintegrates. Moreover, the vacuole appears to play a key role in autophagy; evidence suggests a prosurvival function for autophagy, but other studies propose a prodeath phenotype. Here, we describe and discuss what we know and what we do not know about various PCD pathways and how the host integrates signals to activate salicylic acid and reactive oxygen pathways that orchestrate cell death. We suggest that it is not cell death as such but rather the processes leading to cell death that contribute to the outcome of a given plant-pathogen interaction. PMID:23915134

  11. Understanding Cone Photoreceptor Cell Death in Achromatopsia.

    PubMed

    Carvalho, Livia S; Vandenberghe, Luk H

    2016-01-01

    Colour vision is only achieved in the presence of healthy and functional cone photoreceptors found in the retina. It is an essential component of human vision and usually the first complaint patients undergoing vision degeneration have is the loss of daylight colour vision. Therefore, an understanding of the biology and basic mechanisms behind cone death under the degenerative state of retinal dystrophies and how the activation of the apoptotic pathway is triggered will provide valuable knowledge. It will also have broader applications for a spectrum of visual disorders and will be critical for future advances in translational research. PMID:26427416

  12. Targeting Cell Survival Proteins for Cancer Cell Death

    PubMed Central

    Pandey, Manoj K.; Prasad, Sahdeo; Tyagi, Amit Kumar; Deb, Lokesh; Huang, Jiamin; Karelia, Deepkamal N.; Amin, Shantu G.; Aggarwal, Bharat B.

    2016-01-01

    Escaping from cell death is one of the adaptations that enable cancer cells to stave off anticancer therapies. The key players in avoiding apoptosis are collectively known as survival proteins. Survival proteins comprise the Bcl-2, inhibitor of apoptosis (IAP), and heat shock protein (HSP) families. The aberrant expression of these proteins is associated with a range of biological activities that promote cancer cell survival, proliferation, and resistance to therapy. Several therapeutic strategies that target survival proteins are based on mimicking BH3 domains or the IAP-binding motif or competing with ATP for the Hsp90 ATP-binding pocket. Alternative strategies, including use of nutraceuticals, transcriptional repression, and antisense oligonucleotides, provide options to target survival proteins. This review focuses on the role of survival proteins in chemoresistance and current therapeutic strategies in preclinical or clinical trials that target survival protein signaling pathways. Recent approaches to target survival proteins-including nutraceuticals, small-molecule inhibitors, peptides, and Bcl-2-specific mimetic are explored. Therapeutic inventions targeting survival proteins are promising strategies to inhibit cancer cell survival and chemoresistance. However, complete eradication of resistance is a distant dream. For a successful clinical outcome, pretreatment with novel survival protein inhibitors alone or in combination with conventional therapies holds great promise. PMID:26927133

  13. Measuring Cell Death by Propidium Iodide Uptake and Flow Cytometry.

    PubMed

    Crowley, Lisa C; Scott, Adrian P; Marfell, Brooke J; Boughaba, Jeanne A; Chojnowski, Grace; Waterhouse, Nigel J

    2016-01-01

    Propidium iodide (PI) is a small fluorescent molecule that binds to DNA but cannot passively traverse into cells that possess an intact plasma membrane. PI uptake versus exclusion can be used to discriminate dead cells, in which plasma membranes become permeable regardless of the mechanism of death, from live cells with intact membranes. PI is excited by wavelengths between 400 and 600 nm and emits light between 600 and 700 nm, and is therefore compatible with lasers and photodetectors commonly available in flow cytometers. This protocol for PI staining can be used to quantitate cell death in most modern research facilities and universities. PMID:27371595

  14. Morphological and cytochemical determination of cell death by apoptosis

    PubMed Central

    Sobel, Burton E.; Budd, Ralph C.

    2007-01-01

    Several modes of cell death are now recognized, including necrosis, apoptosis, and autophagy. Oftentimes the distinctions between these various modes may not be apparent, although the precise mode may be physiologically important. Accordingly, it is often desirable to be able to classify the mode of cell death. Apoptosis was originally defined by structural alterations in cells observable by transmitted light and electron microscopy. Today, a wide variety of imaging and cytochemical techniques are available for the investigation of apoptosis. This review will highlight many of these methods, and provide a critique on the advantages and disadvantages associated with them for the specific identification of apoptotic cells in culture and tissues. PMID:18000678

  15. Transcriptomics and functional genomics of ROS-induced cell death regulation by RADICAL-INDUCED CELL DEATH1.

    PubMed

    Brosché, Mikael; Blomster, Tiina; Salojärvi, Jarkko; Cui, Fuqiang; Sipari, Nina; Leppälä, Johanna; Lamminmäki, Airi; Tomai, Gloria; Narayanasamy, Shaman; Reddy, Ramesha A; Keinänen, Markku; Overmyer, Kirk; Kangasjärvi, Jaakko

    2014-02-01

    Plant responses to changes in environmental conditions are mediated by a network of signaling events leading to downstream responses, including changes in gene expression and activation of cell death programs. Arabidopsis thaliana RADICAL-INDUCED CELL DEATH1 (RCD1) has been proposed to regulate plant stress responses by protein-protein interactions with transcription factors. Furthermore, the rcd1 mutant has defective control of cell death in response to apoplastic reactive oxygen species (ROS). Combining transcriptomic and functional genomics approaches we first used microarray analysis in a time series to study changes in gene expression after apoplastic ROS treatment in rcd1. To identify a core set of cell death regulated genes, RCD1-regulated genes were clustered together with other array experiments from plants undergoing cell death or treated with various pathogens, plant hormones or other chemicals. Subsequently, selected rcd1 double mutants were constructed to further define the genetic requirements for the execution of apoplastic ROS induced cell death. Through the genetic analysis we identified WRKY70 and SGT1b as cell death regulators functioning downstream of RCD1 and show that quantitative rather than qualitative differences in gene expression related to cell death appeared to better explain the outcome. Allocation of plant energy to defenses diverts resources from growth. Recently, a plant response termed stress-induced morphogenic response (SIMR) was proposed to regulate the balance between defense and growth. Using a rcd1 double mutant collection we show that SIMR is mostly independent of the classical plant defense signaling pathways and that the redox balance is involved in development of SIMR. PMID:24550736

  16. Transcriptomics and Functional Genomics of ROS-Induced Cell Death Regulation by RADICAL-INDUCED CELL DEATH1

    PubMed Central

    Salojärvi, Jarkko; Cui, Fuqiang; Sipari, Nina; Leppälä, Johanna; Lamminmäki, Airi; Tomai, Gloria; Narayanasamy, Shaman; Reddy, Ramesha A.; Keinänen, Markku; Overmyer, Kirk; Kangasjärvi, Jaakko

    2014-01-01

    Plant responses to changes in environmental conditions are mediated by a network of signaling events leading to downstream responses, including changes in gene expression and activation of cell death programs. Arabidopsis thaliana RADICAL-INDUCED CELL DEATH1 (RCD1) has been proposed to regulate plant stress responses by protein-protein interactions with transcription factors. Furthermore, the rcd1 mutant has defective control of cell death in response to apoplastic reactive oxygen species (ROS). Combining transcriptomic and functional genomics approaches we first used microarray analysis in a time series to study changes in gene expression after apoplastic ROS treatment in rcd1. To identify a core set of cell death regulated genes, RCD1-regulated genes were clustered together with other array experiments from plants undergoing cell death or treated with various pathogens, plant hormones or other chemicals. Subsequently, selected rcd1 double mutants were constructed to further define the genetic requirements for the execution of apoplastic ROS induced cell death. Through the genetic analysis we identified WRKY70 and SGT1b as cell death regulators functioning downstream of RCD1 and show that quantitative rather than qualitative differences in gene expression related to cell death appeared to better explain the outcome. Allocation of plant energy to defenses diverts resources from growth. Recently, a plant response termed stress-induced morphogenic response (SIMR) was proposed to regulate the balance between defense and growth. Using a rcd1 double mutant collection we show that SIMR is mostly independent of the classical plant defense signaling pathways and that the redox balance is involved in development of SIMR. PMID:24550736

  17. A matter of life and cell death.

    PubMed

    Evan, G; Littlewood, T

    1998-08-28

    In multicellular organisms, mutations in somatic cells affecting critical genes that regulate cell proliferation and survival cause fatal cancers. Repair of the damage is one obvious option, although the relative inconsequence of individual cells in metazoans means that it is often a "safer" strategy to ablate the offending cell. Not surprisingly, corruption of the machinery that senses or implements DNA damage greatly predisposes to cancer. Nonetheless, even when oncogenic mutations do occur, there exist potent mechanisms that limit the expansion of affected cells by suppressing their proliferation or triggering their suicide. Growing understanding of these innate mechanisms is suggesting novel therapeutic strategies for cancer.

  18. Acetaminophen Induces Human Neuroblastoma Cell Death through NFKB Activation

    PubMed Central

    Posadas, Inmaculada; Santos, Pablo; Ceña, Valentín

    2012-01-01

    Neuroblastoma resistance to apoptosis may contribute to the aggressive behavior of this tumor. Therefore, it would be relevant to activate endogenous cellular death mechanisms as a way to improve neuroblastoma therapy. We used the neuroblastoma SH-SY5Y cell line as a model to study the mechanisms involved in acetaminophen (AAP)-mediated toxicity by measuring CYP2E1 enzymatic activity, NFkB p65 subunit activation and translocation to the nucleus, Bax accumulation into the mitochondria, cytochrome c release and caspase activation. AAP activates the intrinsic death pathway in the SH-SY5Y human neuroblastoma cell line. AAP metabolism is partially responsible for this activation, because blockade of the cytochrome CYP2E1 significantly reduced but did not totally prevent, AAP-induced SH-SY5Y cell death. AAP also induced NFkB p65 activation by phosphorylation and its translocation to the nucleus, where NFkB p65 increased IL-1β production. This increase contributed to neuroblastoma cell death through a mechanism involving Bax accumulation into the mitochondria, cytochrome c release and caspase3 activation. Blockade of NFkB translocation to the nucleus by the peptide SN50 prevented AAP-mediated cell death and IL-1β production. Moreover, overexpression of the antiapoptotic protein Bcl-xL did not decrease AAP-mediated IL-1β production, but prevented both AAP and IL-1β-mediated cell death. We also confirmed the AAP toxic actions on SK-N-MC neuroepithelioma and U87MG glioblastoma cell lines. The results presented here suggest that AAP activates the intrinsic death pathway in neuroblastoma cells through a mechanism involving NFkB and IL-1β. PMID:23166834

  19. External and internal triggers of cell death in yeast.

    PubMed

    Falcone, Claudio; Mazzoni, Cristina

    2016-06-01

    In recent years, yeast was confirmed as a useful eukaryotic model system to decipher the complex mechanisms and networks occurring in higher eukaryotes, particularly in mammalian cells, in physiological as well in pathological conditions. This article focuses attention on the contribution of yeast in the study of a very complex scenario, because of the number and interconnection of pathways, represented by cell death. Yeast, although it is a unicellular organism, possesses the basal machinery of different kinds of cell death occurring in higher eukaryotes, i.e., apoptosis, regulated necrosis and autophagy. Here we report the current knowledge concerning the yeast orthologs of main mammalian cell death regulators and executors, the role of organelles and compartments, and the cellular phenotypes observed in the different forms of cell death in response to external and internal triggers. Thanks to the ease of genetic manipulation of this microorganism, yeast strains expressing human genes that promote or counteract cell death, onset of tumors and neurodegenerative diseases have been constructed. The effects on yeast cells of some of these genes are also presented.

  20. Regulation of cell death receptor S-nitrosylation and apoptotic signaling by Sorafenib in hepatoblastoma cells.

    PubMed

    Rodríguez-Hernández, A; Navarro-Villarán, E; González, R; Pereira, S; Soriano-De Castro, L B; Sarrias-Giménez, A; Barrera-Pulido, L; Álamo-Martínez, J M; Serrablo-Requejo, A; Blanco-Fernández, G; Nogales-Muñoz, A; Gila-Bohórquez, A; Pacheco, D; Torres-Nieto, M A; Serrano-Díaz-Canedo, J; Suárez-Artacho, G; Bernal-Bellido, C; Marín-Gómez, L M; Barcena, J A; Gómez-Bravo, M A; Padilla, C A; Padillo, F J; Muntané, J

    2015-12-01

    Nitric oxide (NO) plays a relevant role during cell death regulation in tumor cells. The overexpression of nitric oxide synthase type III (NOS-3) induces oxidative and nitrosative stress, p53 and cell death receptor expression and apoptosis in hepatoblastoma cells. S-nitrosylation of cell death receptor modulates apoptosis. Sorafenib is the unique recommended molecular-targeted drug for the treatment of patients with advanced hepatocellular carcinoma. The present study was addressed to elucidate the potential role of NO during Sorafenib-induced cell death in HepG2 cells. We determined the intra- and extracellular NO concentration, cell death receptor expression and their S-nitrosylation modifications, and apoptotic signaling in Sorafenib-treated HepG2 cells. The effect of NO donors on above parameters has also been determined. Sorafenib induced apoptosis in HepG2 cells. However, low concentration of the drug (10nM) increased cell death receptor expression, as well as caspase-8 and -9 activation, but without activation of downstream apoptotic markers. In contrast, Sorafenib (10 µM) reduced upstream apoptotic parameters but increased caspase-3 activation and DNA fragmentation in HepG2 cells. The shift of cell death signaling pathway was associated with a reduction of S-nitrosylation of cell death receptors in Sorafenib-treated cells. The administration of NO donors increased S-nitrosylation of cell death receptors and overall induction of cell death markers in control and Sorafenib-treated cells. In conclusion, Sorafenib induced alteration of cell death receptor S-nitrosylation status which may have a relevant repercussion on cell death signaling in hepatoblastoma cells.

  1. The life and death of a B cell.

    PubMed

    Defrance, Thierry; Casamayor-Pallejà, Montserrat; Krammer, Peter H

    2002-01-01

    Regulation of apoptosis in the B cell lineage has implications for homeostasis, quality control of the antibody response, and tolerance. In this chapter we examine the different checkpoints that control life and death decisions of B cells during the antigen-independent and antigen-dependent phases of their development. We discuss the cell death mechanism involved in elimination of unwanted B cells at different stages of their development as well as the signals that trigger or repress the apoptotic process. At the steady state, before or after development of an immune response, B cell apoptosis ensures that the antigen receptor (BCR) on newly produced B cells is functional and does not recognize self-antigens with high avidity. It also ensures that the size of the peripheral B cell compartment remains constant in spite of the continuous input of B cells from the bone marrow. All these processes are controlled by the mitochondrial death pathway and are thus perturbed by overexpression of the antiapoptotic members of the bcl-2 gene family. By contrast, the death receptor pathway plays a prominent role during the antigen-dependent phase of B cell development. Three sets of membrane molecules stand as crucial regulators of B cell survival. First, the BCR which plays a central but ambiguous role. On the one hand, it triggers death of B cells that recognize self-antigens or have been exposed to repeated antigenic stimulations. On the other hand, it promotes survival of the peripheral mature B cell pool and protects activated B cells from CD95-induced killing. Second, the death receptor Fas/CD95 which is instrumental in censoring B cells activated in a bystander fashion at the initiation of the response to T-dependent antigens. It also drives elimination of low-affinity and self-reactive B cell clones that arise through the process of somatic mutations during the germinal center reaction. As such, it contributes to the affinity maturation of the antibody response. Finally

  2. Therapeutic approaches to preventing cell death in Huntington disease

    PubMed Central

    Kaplan, Anna; Stockwell, Brent R.

    2012-01-01

    Neurodegenerative diseases affect the lives of millions of patients and their families. Due to the complexity of these diseases and our limited understanding of their pathogenesis, the design of therapeutic agents that can effectively treat these diseases has been challenging. Huntington disease (HD) is one of several neurological disorders with few therapeutic options. HD, like numerous other neurodegenerative diseases, involves extensive neuronal cell loss. One potential strategy to combat HD and other neurodegenerative disorders is to intervene in the execution of neuronal cell death. Inhibiting neuronal cell death pathways may slow the development of neurodegeneration. However, discovering small molecule inhibitors of neuronal cell death remains a significant challenge. Here, we review candidate therapeutic targets controlling cell death mechanisms that have been the focus of research in HD, as well as an emerging strategy that has been applied to developing small molecule inhibitors—fragment-based drug discovery (FBDD). FBDD has been successfully used in both industry and academia to identify selective and potent small molecule inhibitors, with a focus on challenging proteins that are not amenable to traditional high-throughput screening approaches. FBDD has been used to generate potent leads, pre-clinical candidates, and has led to the development of an FDA approved drug. This approach can be valuable for identifying modulators of cell-death-regulating proteins; such compounds may prove to be the key to halting the progression of HD and other neurodegenerative disorders. PMID:22967354

  3. Therapeutic approaches to preventing cell death in Huntington disease.

    PubMed

    Kaplan, Anna; Stockwell, Brent R

    2012-12-01

    Neurodegenerative diseases affect the lives of millions of patients and their families. Due to the complexity of these diseases and our limited understanding of their pathogenesis, the design of therapeutic agents that can effectively treat these diseases has been challenging. Huntington disease (HD) is one of several neurological disorders with few therapeutic options. HD, like numerous other neurodegenerative diseases, involves extensive neuronal cell loss. One potential strategy to combat HD and other neurodegenerative disorders is to intervene in the execution of neuronal cell death. Inhibiting neuronal cell death pathways may slow the development of neurodegeneration. However, discovering small molecule inhibitors of neuronal cell death remains a significant challenge. Here, we review candidate therapeutic targets controlling cell death mechanisms that have been the focus of research in HD, as well as an emerging strategy that has been applied to developing small molecule inhibitors-fragment-based drug discovery (FBDD). FBDD has been successfully used in both industry and academia to identify selective and potent small molecule inhibitors, with a focus on challenging proteins that are not amenable to traditional high-throughput screening approaches. FBDD has been used to generate potent leads, pre-clinical candidates, and has led to the development of an FDA approved drug. This approach can be valuable for identifying modulators of cell-death-regulating proteins; such compounds may prove to be the key to halting the progression of HD and other neurodegenerative disorders. PMID:22967354

  4. Solamargine triggers hepatoma cell death through apoptosis

    PubMed Central

    XIE, XIAODONG; ZHU, HAITAO; YANG, HUIJIAN; HUANG, WENSI; WU, YINGYING; WANG, YING; LUO, YANLING; WANG, DONGQING; SHAO, GENBAO

    2015-01-01

    Solamargine (SM), a steroidal alkaloid glycoside extracted from the traditional Chinese herb Solanum incanum, has been evidenced to inhibit the growth and induce apoptosis in a number of human cancer cell lines. In the present study, the anticancer effect of SM and underlying molecular mechanism of SM-induced apoptosis were investigated on the human hepatocellular carcinoma cells, SMMC7721 and HepG2. The proliferation effects of SM on the SMMC7721 and HepG2 cell lines were evaluated using MTT and colony formation assays. In addition, the percentage of apoptosis was measured using an Annexin V/propidium iodide staining method and the cell cycle distribution mediated by SM was analyzed using flow cytometry. The expression levels of B-cell lymphoma-2 (Bcl-2), Bcl-2-associated X protein (Bax), caspase-3, caspase-9, proliferating cell nuclear antigen (pcna) and Ki67 proteins were examined to further demonstrate the proliferate and apoptosis effects of SM on the hepatoma cells. The results indicated that SM effectively inhibited hepatoma cell proliferation and promoted apoptosis. SM resulted in cell cycle arrest at the G2/M phase in the two cell lines. In addition, SM downregulated the levels of proliferation-associated (Ki67 and pcna) and anti-apoptotic (Bcl-2) proteins, and promoted the activity of apoptosis-associated proteins (Bax, caspase-3 and caspase-9). Therefore, the activation of the Bcl-2/Bax and caspase signaling pathways may be involved in the SM-induced apoptosis of hepatoma cells. PMID:26170994

  5. Microenvironmental Effects of Cell Death in Malignant Disease.

    PubMed

    Gregory, Christopher D; Ford, Catriona A; Voss, Jorine J L P

    2016-01-01

    Although apoptosis is well recognized as a cell death program with clear anticancer roles, accumulating evidence linking apoptosis with tissue repair and regeneration indicates that its relationship with malignant disease is more complex than previously thought. Here we review how the responses of neighboring cells in the microenvironment of apoptotic tumor cells may contribute to the cell birth/cell death disequilibrium that provides the basis for cancerous tissue emergence and growth. We describe the bioactive properties of apoptotic cells and consider, in particular, how apoptosis of tumor cells can engender a range of responses including pro-oncogenic signals having proliferative, angiogenic, reparatory, and immunosuppressive features. Drawing on the parallels between wound healing, tissue regeneration and cancer, we propose the concept of the "onco-regenerative niche," a cell death-driven generic network of tissue repair and regenerative mechanisms that are hijacked in cancer. Finally, we consider how the responses to cell death in tumors can be targeted to provide more effective and long-lasting therapies. PMID:27558817

  6. Lung epithelial cell death induced by oil-dispersant mixtures.

    PubMed

    Wang, He; Shi, Yongli; Major, Danielle; Yang, Zhanjun

    2012-08-01

    The dispersants used in oil spill disasters are claimed to be safe, but increased solubility of high-molecular-weight components in crude oil is of public health concern. The water-accommodated fractions (WAF) of crude oil mixed with dispersants may become airborne and cause lung epithelial damage when inhaled. This study was designed to examine the cell death and related death pathways of lung epithelial cells in response to WAF. Cultured A549 cells were treated for 2 or 24h with different concentrations of WAF. The WAF was prepared by mixing each of the dispersants (Corexit EC9527A, Corexit EC9500A and Corexit EC9580A) with crude oil for extraction with PBS. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide MTT assay, lactate dehydrogenase assay, morphology and cleaved caspase 9 protein, and microtubule-associated protein 1 light chain 3 were all used to measure cell viability, necrosis, apoptosis and autophagy quantitation, respectively. Results showed that the WAF of oil-dispersant mixtures caused cell death in the lung epithelial cells, in a dose-dependent manner, with the major cellular pathways of necrosis and apoptosis involved. Autophagy also occurred in cells exposed to WAF mixtures at lower concentrations before any detectable cell death, indicating greater sensitivity to WAF exposure. The three types of cell behavior, namely necrosis, apoptosis and autophagy, may play different roles in oil spill-related respiratory disorders. PMID:22504303

  7. RACK-1 overexpression protects against goniothalamin-induced cell death

    PubMed Central

    Inayat-Hussain, S.H.; Wong, L.T.; Chan, K.M.; Rajab, N.F.; Din, L.B.; Harun, R.; Kizilors, A.; Saxena, N.; Mourtada-Maarabouni, M.; Farzaneh, F.; Williams, G.T.

    2009-01-01

    Goniothalamin, a styryllactone, has been shown to induce cytotoxicity via apoptosis in several tumor cell lines. In this study, we have examined the potential role of several genes, which were stably transfected into T-cell lines and which regulate apoptosis in different ways, on goniothalamin-induced cell death. Overexpression of full-length receptor for activated protein C-kinase 1 (RACK-1) and pc3n3, which up-regulates endogenous RACK-1, in both Jurkat and W7.2 T cells resulted in inhibition of goniothalamin-induced cell death as assessed by MTT and clonogenic assays. However, overexpression of rFau (antisense sequence to Finkel–Biskis–Reilly murine sarcoma virus-associated ubiquitously expressed gene) in W7.2 cells did not confer resistance to goniothalamin-induced cell death. Etoposide, a clinically used cytotoxic agent, was equipotent in causing cytotoxicity in all the stable transfectants. Assessment of DNA damage by Comet assay revealed goniothalamin-induced DNA strand breaks as early as 1 h in vector control but this effect was inhibited in RACK-1 and pc3n3 stably transfected W7.2 cells. This data demonstrate that RACK-1 plays a crucial role in regulating cell death signalling pathways induced by goniothalamin. PMID:19698770

  8. Detection of Apoptotic Versus Autophagic Cell Death by Flow Cytometry.

    PubMed

    Sica, Valentina; Maiuri, M Chiara; Kroemer, Guido; Galluzzi, Lorenzo

    2016-01-01

    Different modes of regulated cell death (RCD) can be initiated by distinct molecular machineries and their morphological manifestations can be difficult to discriminate. Moreover, cells responding to stress often activate an adaptive response centered around autophagy, and whether such a response is cytoprotective or cytotoxic cannot be predicted based on morphological parameters only. Molecular definitions are therefore important to understand various RCD subroutines from a mechanistic perspective. In vitro, various forms of RCD including apoptosis and autophagic cell death can be easily discriminated from each other with assays that involve chemical or pharmacological interventions targeting key components of either pathway. Here, we detail a straightforward method to discriminate apoptosis from autophagic cell death by flow cytometry, based on the broad-spectrum caspase inhibitor Z-VAD-fmk and the genetic inhibition of ATG5.

  9. Porcine circovirus-2 capsid protein induces cell death in PK15 cells

    SciTech Connect

    Walia, Rupali; Dardari, Rkia Chaiyakul, Mark; Czub, Markus

    2014-11-15

    Studies have shown that Porcine circovirus (PCV)-2 induces apoptosis in PK15 cells. Here we report that cell death is induced in PCV2b-infected PK15 cells that express Capsid (Cap) protein and this effect is enhanced in interferon gamma (IFN-γ)-treated cells. We further show that transient PCV2a and 2b-Cap protein expression induces cell death in PK15 cells at rate similar to PCV2 infection, regardless of Cap protein localization. These data suggest that Cap protein may have the capacity to trigger different signaling pathways involved in cell death. Although further investigation is needed to gain deeper insights into the nature of the pathways involved in Cap-induced cell death, this study provides evidence that PCV2-induced cell death in kidney epithelial PK15 cells can be mapped to the Cap protein and establishes the need for future research regarding the role of Cap-induced cell death in PCV2 pathogenesis. - Highlights: • IFN-γ enhances PCV2 replication that leads to cell death in PK15 cells. • IFN-γ enhances nuclear localization of the PCV2 Capsid protein. • Transient PCV2a and 2b-Capsid protein expression induces cell death. • Cell death is not dictated by specific Capsid protein sub-localization.

  10. Entamoeba histolytica induces cell death of HT29 colonic epithelial cells via NOX1-derived ROS.

    PubMed

    Kim, Kyeong Ah; Kim, Ju Young; Lee, Young Ah; Min, Arim; Bahk, Young Yil; Shin, Myeong Heon

    2013-02-01

    Entamoeba histolytica, which causes amoebic colitis and occasionally liver abscess in humans, is able to induce host cell death. However, signaling mechanisms of colon cell death induced by E. histolytica are not fully elucidated. In this study, we investigated the signaling role of NOX in cell death of HT29 colonic epithelial cells induced by E. histolytica. Incubation of HT29 cells with amoebic trophozoites resulted in DNA fragmentation that is a hallmark of apoptotic cell death. In addition, E. histolytica generate intracellular reactive oxygen species (ROS) in a contact-dependent manner. Inhibition of intracellular ROS level with treatment with DPI, an inhibitor of NADPH oxidases (NOXs), decreased Entamoeba-induced ROS generation and cell death in HT29 cells. However, pan-caspase inhibitor did not affect E. histolytica-induced HT29 cell death. In HT29 cells, catalytic subunit NOX1 and regulatory subunit Rac1 for NOX1 activation were highly expressed. We next investigated whether NADPH oxidase 1 (NOX1)-derived ROS is closely associated with HT29 cell death induced by E. histolytica. Suppression of Rac1 by siRNA significantly inhibited Entamoeba-induced cell death. Moreover, knockdown of NOX1 by siRNA, effectively inhibited E. histolytica-triggered DNA fragmentation in HT29 cells. These results suggest that NOX1-derived ROS is required for apoptotic cell death in HT29 colon epithelial cells induced by E. histolytica.

  11. Technological advances in real-time tracking of cell death

    PubMed Central

    Skommer, Joanna; Darzynkiewicz, Zbigniew; Wlodkowic, Donald

    2010-01-01

    Cell population can be viewed as a quantum system, which like Schrödinger’s cat exists as a combination of survival- and death-allowing states. Tracking and understanding cell-to-cell variability in processes of high spatio-temporal complexity such as cell death is at the core of current systems biology approaches. As probabilistic modeling tools attempt to impute information inaccessible by current experimental approaches, advances in technologies for single-cell imaging and omics (proteomics, genomics, metabolomics) should go hand in hand with the computational efforts. Over the last few years we have made exciting technological advances that allow studies of cell death dynamically in real-time and with the unprecedented accuracy. These approaches are based on innovative fluorescent assays and recombinant proteins, bioelectrical properties of cells, and more recently also on state-of-the-art optical spectroscopy. Here, we review current status of the most innovative analytical technologies for dynamic tracking of cell death, and address the interdisciplinary promises and future challenges of these methods. PMID:20519963

  12. Ceramide path in human lung cell death.

    PubMed

    Chan, C; Goldkorn, T

    2000-04-01

    Lung epithelium plays a significant role in modulating the inflammatory response to lung injury. Airway epithelial cells are targeted by hydrogen peroxide (H(2)O(2)) and oxygen radicals, which are agents commonly produced during inflammatory processes. The mechanisms and molecular sites affected by H(2)O(2) are largely unknown but may involve the induction of sphingomyelin (SM) hydrolysis to generate ceramide, which serves as a second messenger in initiating an apoptotic response. Here we show that exposure of human airway epithelial (HAE) cells to 50 to 100 microM H(2)O(2) induces within 5 to 10 min a greater than 2-fold activation of neutral sphingomyelinase activity with concomitant SM hydrolysis, ceramide generation, and apoptosis. On the other hand, activation of protein kinase C (PKC) by 12-O-tetradecanoylphorbol-13-acetate inhibits both H(2)O(2)-induced ceramide production and apoptosis. The apoptotic response could be restored by the addition of 25 microM cell-permeant C6-ceramide. These findings indicate that ceramide, the product of SM hydrolysis, plays an important role in H(2)O(2)-induced apoptosis in HAE cells, and that PKC counteracts ceramide-mediated apoptosis in these cells. We suggest that the mediation of epithelial cell apoptosis by ceramide and its inhibition by PKC constitute a central mechanism by which inflammatory processes are modulated in the epithelium of the lung.

  13. Identification of the death zone: a spatially restricted region for programmed cell death that sculpts the fly eye.

    PubMed

    Monserrate, J P; Brachmann, C Baker

    2007-02-01

    Programmed cell death (PCD) sculpts many developing tissues. The final patterning step of the Drosophila retina is the elimination, through PCD, of a subset of interommatidial lattice cells during pupation. It is not understood how this process is spatially regulated to ensure that cells die in the proper positions. To address this, we observed PCD of lattice cells in the pupal retina in real time. This live-visualization method demonstrates that lattice cell apoptosis is a highly specific process. In all, 85% of lattice cells die in exclusive 'death zone' positions between adjacent ommatidia. In contrast, cells that make specific contacts with primary pigment cells are protected from death. Two signaling pathways, Drosophila epidermal growth factor receptor (dEgfr) and Notch, that are thought to be central to the regulation of lattice cell survival and death, are not sufficient to establish the death zone. Thus, application of live visualization to the fly eye gives new insight into a dynamic developmental process.

  14. Signal transduction events in aluminum-induced cell death in tomato suspension cells.

    PubMed

    Yakimova, Elena T; Kapchina-Toteva, Veneta M; Woltering, Ernst J

    2007-06-01

    In this study, some of the signal transduction events involved in AlCl(3)-induced cell death in tomato (Lycopersicon esculentum Mill.) suspension cells were elucidated. Cells treated with 100 microM AlCl(3) showed typical features of programmed cell death (PCD) such as nuclear and cytoplasmic condensation. Cell death was effectively inhibited by protease and human caspase inhibitors indicating a cell death execution mechanism with similarities to animal apoptosis. Cell death was suppressed by application of antoxidants and by inhibitors of phospholipase C (PLC), phospholipase D (PLD) and ethylene signalling pathways. The results suggest that low concentrations of heavy metal ions stimulate both PLC and PLD signalling pathways leading to the production of reactive oxygen species (ROS) and subsequent cell death executed by caspase-like proteases.

  15. Cell death and autophagy: cytokines, drugs, and nutritional factors.

    PubMed

    Bursch, Wilfried; Karwan, Anneliese; Mayer, Miriam; Dornetshuber, Julia; Fröhwein, Ulrike; Schulte-Hermann, Rolf; Fazi, Barbara; Di Sano, Federica; Piredda, Lucia; Piacentini, Mauro; Petrovski, Goran; Fésüs, László; Gerner, Christopher

    2008-12-30

    Cells may use multiple pathways to commit suicide. In certain contexts, dying cells generate large amounts of autophagic vacuoles and clear large proportions of their cytoplasm, before they finally die, as exemplified by the treatment of human mammary carcinoma cells with the anti-estrogen tamoxifen (TAM, < or = 1 microM). Protein analysis during autophagic cell death revealed distinct proteins of the nuclear fraction including GST-pi and some proteasomal subunit constituents to be affected during autophagic cell death. Depending on the functional status of caspase-3, MCF-7 cells may switch between autophagic and apoptotic features of cell death [Fazi, B., Bursch, W., Fimia, G.M., Nardacci R., Piacentini, M., Di Sano, F., Piredda, L., 2008. Fenretinide induces autophagic cell death in caspase-defective breast cancer cells. Autophagy 4(4), 435-441]. Furthermore, the self-destruction of MCF-7 cells was found to be completed by phagocytosis of cell residues [Petrovski, G., Zahuczky, G., Katona, K., Vereb, G., Martinet, W., Nemes, Z., Bursch, W., Fésüs, L., 2007. Clearance of dying autophagic cells of different origin by professional and non-professional phagocytes. Cell Death Diff. 14 (6), 1117-1128]. Autophagy also constitutes a cell's strategy of defense upon cell damage by eliminating damaged bulk proteins/organelles. This biological condition may be exemplified by the treatment of MCF-7 cells with a necrogenic TAM-dose (10 microM), resulting in the lysis of almost all cells within 24h. However, a transient (1h) challenge of MCF-7 cells with the same dose allowed the recovery of cells involving autophagy. Enrichment of chaperones in the insoluble cytoplasmic protein fraction indicated the formation of aggresomes, a potential trigger for autophagy. In a further experimental model HL60 cells were treated with TAM, causing dose-dependent distinct responses: 1-5 microM TAM, autophagy predominant; 7-9 microM, apoptosis predominant; 15 microM, necrosis. These phenomena

  16. Glycobiology of cell death: when glycans and lectins govern cell fate

    PubMed Central

    Lichtenstein, R G; Rabinovich, G A

    2013-01-01

    Although one typically thinks of carbohydrates as associated with cell growth and viability, glycosylation also has an integral role in many processes leading to cell death. Glycans, either alone or complexed with glycan-binding proteins, can deliver intracellular signals or control extracellular processes that promote initiation, execution and resolution of cell death programs. Herein, we review the role of glycans and glycan-binding proteins as essential components of the cell death machinery during physiologic and pathologic settings. PMID:23703323

  17. Apoptotic photoreceptor cell death in mouse models of retinitis pigmentosa.

    PubMed Central

    Portera-Cailliau, C; Sung, C H; Nathans, J; Adler, R

    1994-01-01

    Retinitis pigmentosa (RP) is a group of inherited human diseases in which photoreceptor degeneration leads to visual loss and eventually to blindness. Although mutations in the rhodopsin, peripherin, and cGMP phosphodiesterase genes have been identified in some forms of RP, it remains to be determined whether these mutations lead to photoreceptor cell death through necrotic or apoptotic mechanisms. In this paper, we report a test of the hypothesis that photoreceptor cell death occurs by an apoptotic mechanism in three mouse models of RP: retinal degeneration slow (rds) caused by a peripherin mutation, retinal degeneration (rd) caused by a defect in cGMP phosphodiesterase, and transgenic mice carrying a rhodopsin Q344ter mutation responsible for autosomal dominant RP. Two complementary techniques were used to detect apoptosis-specific internucleosomal DNA fragmentation: agarose gel electrophoresis and in situ labeling of apoptotic cells by terminal dUTP nick end labeling. Both methods showed extensive apoptosis of photoreceptors in all three mouse models of retinal degeneration. We also show that apoptotic death occurs in the retina during normal development, suggesting that different mechanisms can cause photoreceptor death by activating an intrinsic death program in these cells. These findings raise the possibility that retinal degenerations may be slowed by interfering with the apoptotic mechanism itself. Images PMID:8302876

  18. Oxidative Stress and Programmed Cell Death in Yeast

    PubMed Central

    Farrugia, Gianluca; Balzan, Rena

    2012-01-01

    Yeasts, such as Saccharomyces cerevisiae, have long served as useful models for the study of oxidative stress, an event associated with cell death and severe human pathologies. This review will discuss oxidative stress in yeast, in terms of sources of reactive oxygen species (ROS), their molecular targets, and the metabolic responses elicited by cellular ROS accumulation. Responses of yeast to accumulated ROS include upregulation of antioxidants mediated by complex transcriptional changes, activation of pro-survival pathways such as mitophagy, and programmed cell death (PCD) which, apart from apoptosis, includes pathways such as autophagy and necrosis, a form of cell death long considered accidental and uncoordinated. The role of ROS in yeast aging will also be discussed. PMID:22737670

  19. Programmed Cell Death During Female Gametophyte Development

    SciTech Connect

    Drews, Gary, N.

    2004-09-15

    Endosperm is a storage tissue in the angiosperm seed that is important both biologically and agriculturally. Endosperm is biologically important because it provides nutrients to the embryo during seed development and agriculturally important because it is a significant source of food, feed, and industrial raw materials. Approximately two-thirds of human calories are derived from endosperm, either directly or indirectly through animal feed. Furthermore, endosperm is used as a raw material for numerous industrial products including ethanol. A major event in endosperm development is the transition between the syncytial phase, during which the endosperm nuclei undergo many rounds of mitosis without cytokinesis, and the cellularized phase, during which cell walls form around the endosperm nuclei. Understanding how the syncytial-cellular transition is regulated is agriculturally important because it influences seed size, seed sink strength, and grain weight. However, the molecular processes controlling this transition are not understood. This project led to the identification of the AGL62 gene that regulates the syncytial-cellular transition during endosperm development. AGL62 is expressed during the syncytial phase and suppresses endosperm cellularization during this period. AGL62 most likely does so by suppressing the expression of genes required for cellularization. At the end of the syncytial phase, the FIS PcG complex suppresses AGL62 expression, which allows expression of the cellularization genes and triggers the initiation of the cellularized phase. Endosperm arises following fertilization of the central cell within the female gametophyte. This project also led to the identification of the AGL80 gene that is required for development of the central cell into the endosperm. Within the ovule and seed, AGL80 is expressed exclusively in the central cell and uncellularized endosperm. AGL80 is required for expression of several central cell-expressed genes, including

  20. How does metabolism affect cell death in cancer?

    PubMed

    Villa, Elodie; Ricci, Jean-Ehrland

    2016-07-01

    In cancer research, identifying a specificity of tumor cells compared with 'normal' proliferating cells for targeted therapy is often considered the Holy Grail for researchers and clinicians. Although diverse in origin, most cancer cells share characteristics including the ability to escape cell death mechanisms and the utilization of different methods of energy production. In the current paradigm, aerobic glycolysis is considered the central metabolic characteristic of cancer cells (Warburg effect). However, recent data indicate that cancer cells also show significant changes in other metabolic pathways. Indeed, it was recently suggested that Kreb's cycle, pentose phosphate pathway intermediates, and essential and nonessential amino acids have key roles. Renewed interest in the fact that cancer cells have to reprogram their metabolism in order to proliferate or resist treatment must take into consideration the ability of tumor cells to adapt their metabolism to the local microenvironment (low oxygen, low nutrients). This variety of metabolic sources might be either a strength, resulting in infinite possibilities for adaptation and increased ability to resist chemotherapy-induced death, or a weakness that could be targeted to kill cancer cells. Here, we discuss recent insights showing how energetic metabolism may regulate cell death and how this might be relevant for cancer treatment.

  1. Danger signalling during cancer cell death: origins, plasticity and regulation

    PubMed Central

    Garg, A D; Martin, S; Golab, J; Agostinis, P

    2014-01-01

    Accumulating data indicates that following anti-cancer treatments, cancer cell death can be perceived as immunogenic or tolerogenic by the immune system. The former is made possible due to the ability of certain anti-cancer modalities to induce immunogenic cell death (ICD) that is associated with the emission of damage-associated molecular patterns (DAMPs), which assist in unlocking a sequence of events leading to the development of anti-tumour immunity. In response to ICD inducers, activation of endoplasmic reticulum (ER) stress has been identified to be indispensable to confer the immunogenic character of cancer cell death, due to its ability to coordinate the danger signalling pathways responsible for the trafficking of vital DAMPs and subsequent anti-cancer immune responses. However, in recent times, certain processes apart from ER stress have emerged (e.g., autophagy and possibly viral response-like signature), which have the ability to influence danger signalling. In this review, we discuss the molecular nature, emerging plasticity in the danger signalling mechanisms and immunological impact of known DAMPs in the context of immunogenic cancer cell death. We also discuss key effector mechanisms modulating the interface between dying cancer cells and the immune cells, which we believe are crucial for the therapeutic relevance of ICD in the context of human cancers, and also discuss the influence of experimental conditions and animal models on these. PMID:23686135

  2. Cell death in protists without mitochondria.

    PubMed

    Chose, Olivier; Sarde, Claude-Olivier; Noël, Christophe; Gerbod, Delphine; Jimenez, Juan-Carlos; Brenner, Catherine; Capron, Monique; Viscogliosi, Eric; Roseto, Alberto

    2003-12-01

    Some protozoans, such as Trichomonad species, do not possess mitochondria. Most of the time, they harbor another type of membrane-bounded organelle, called hydrogenosome from its capacity to produce H(2). This is the case for the human parasite Trichomonas vaginalis. Some other parasites, such as the protist Giardia lamblia, do not harbor any of these organelles. From this observation arises naturally a naive question: How do cells die when the mitochondrion, the cornerstone of apoptotic process, is absent? Data strongly suggest that the mitochondrion and the hydrogenosome arose from a common ancestral endosymbiont. But hydrogenosomes do not appear to directly substitute for mitochondria in apoptotic functions. Thus, it appears judicious to examine more closely the genome of unicellular cells, which do not harbor mitochondria, and search for new molecules that could participate in the apoptotic process in these microorganisms. PMID:15033707

  3. Cell death in protists without mitochondria.

    PubMed

    Chose, Olivier; Sarde, Claude-Olivier; Noël, Christophe; Gerbod, Delphine; Jimenez, Juan-Carlos; Brenner, Catherine; Capron, Monique; Viscogliosi, Eric; Roseto, Alberto

    2003-12-01

    Some protozoans, such as Trichomonad species, do not possess mitochondria. Most of the time, they harbor another type of membrane-bounded organelle, called hydrogenosome from its capacity to produce H(2). This is the case for the human parasite Trichomonas vaginalis. Some other parasites, such as the protist Giardia lamblia, do not harbor any of these organelles. From this observation arises naturally a naive question: How do cells die when the mitochondrion, the cornerstone of apoptotic process, is absent? Data strongly suggest that the mitochondrion and the hydrogenosome arose from a common ancestral endosymbiont. But hydrogenosomes do not appear to directly substitute for mitochondria in apoptotic functions. Thus, it appears judicious to examine more closely the genome of unicellular cells, which do not harbor mitochondria, and search for new molecules that could participate in the apoptotic process in these microorganisms.

  4. DAMPs from Cell Death to New Life

    PubMed Central

    Vénéreau, Emilie; Ceriotti, Chiara; Bianchi, Marco Emilio

    2015-01-01

    Our body handles tissue damage by activating the immune system in response to intracellular molecules released by injured tissues [damage-associated molecular patterns (DAMPs)], in a similar way as it detects molecular motifs conserved in pathogens (pathogen-associated molecular patterns). DAMPs are molecules that have a physiological role inside the cell, but acquire additional functions when they are exposed to the extracellular environment: they alert the body about danger, stimulate an inflammatory response, and finally promote the regeneration process. Beside their passive release by dead cells, some DAMPs can be secreted or exposed by living cells undergoing a life-threatening stress. DAMPs have been linked to inflammation and related disorders: hence, inhibition of DAMP-mediated inflammatory responses is a promising strategy to improve the clinical management of infection- and injury-elicited inflammatory diseases. However, it is important to consider that DAMPs are not only danger signals but also central players in tissue repair. Indeed, some DAMPs have been studied for their role in tissue healing after sterile or infection-associated inflammation. This review is focused on two exemplary DAMPs, HMGB1 and adenosine triphosphate, and their contribution to both inflammation and tissue repair. PMID:26347745

  5. Sensory hair cell death and regeneration in fishes.

    PubMed

    Monroe, Jerry D; Rajadinakaran, Gopinath; Smith, Michael E

    2015-01-01

    Sensory hair cells are specialized mechanotransductive receptors required for hearing and vestibular function. Loss of hair cells in humans and other mammals is permanent and causes reduced hearing and balance. In the early 1980's, it was shown that hair cells continue to be added to the inner ear sensory epithelia in cartilaginous and bony fishes. Soon thereafter, hair cell regeneration was documented in the chick cochlea following acoustic trauma. Since then, research using chick and other avian models has led to great insights into hair cell death and regeneration. However, with the rise of the zebrafish as a model organism for studying disease and developmental processes, there has been an increased interest in studying sensory hair cell death and regeneration in its lateral line and inner ears. Advances derived from studies in zebrafish and other fish species include understanding the effect of ototoxins on hair cells and finding otoprotectants to mitigate ototoxin damage, the role of cellular proliferation vs. direct transdifferentiation during hair cell regeneration, and elucidating cellular pathways involved in the regeneration process. This review will summarize research on hair cell death and regeneration using fish models, indicate the potential strengths and weaknesses of these models, and discuss several emerging areas of future studies.

  6. Sensory hair cell death and regeneration in fishes

    PubMed Central

    Monroe, Jerry D.; Rajadinakaran, Gopinath; Smith, Michael E.

    2015-01-01

    Sensory hair cells are specialized mechanotransductive receptors required for hearing and vestibular function. Loss of hair cells in humans and other mammals is permanent and causes reduced hearing and balance. In the early 1980’s, it was shown that hair cells continue to be added to the inner ear sensory epithelia in cartilaginous and bony fishes. Soon thereafter, hair cell regeneration was documented in the chick cochlea following acoustic trauma. Since then, research using chick and other avian models has led to great insights into hair cell death and regeneration. However, with the rise of the zebrafish as a model organism for studying disease and developmental processes, there has been an increased interest in studying sensory hair cell death and regeneration in its lateral line and inner ears. Advances derived from studies in zebrafish and other fish species include understanding the effect of ototoxins on hair cells and finding otoprotectants to mitigate ototoxin damage, the role of cellular proliferation vs. direct transdifferentiation during hair cell regeneration, and elucidating cellular pathways involved in the regeneration process. This review will summarize research on hair cell death and regeneration using fish models, indicate the potential strengths and weaknesses of these models, and discuss several emerging areas of future studies. PMID:25954154

  7. Snail1 is required for the maintenance of the pancreatic acinar phenotype

    PubMed Central

    Loubat-Casanovas, Jordina; Peña, Raúl; Gonzàlez, Núria; Alba-Castellón, Lorena; Rosell, Santi; Francí, Clara; Navarro, Pilar; de Herreros, Antonio García

    2016-01-01

    The Snail1 transcriptional factor is required for correct embryonic development, yet its expression in adult animals is very limited and its functional roles are not evident. We have now conditionally inactivated Snail1 in adult mice and analyzed the phenotype of these animals. Snail1 ablation rapidly altered pancreas structure: one month after Snail1 depletion, acinar cells were markedly depleted, and pancreas accumulated adipose tissue. Snail1 expression was not detected in the epithelium but was in pancreatic mesenchymal cells (PMCs). Snail1 ablation in cultured PMCs downregulated the expression of several β-catenin/Tcf-4 target genes, modified the secretome of these cells and decreased their ability to maintain acinar markers in cultured pancreas cells. Finally, Snail1 deficiency modified the phenotype of pancreatic tumors generated in transgenic mice expressing c-myc under the control of the elastase promoter. Specifically, Snail1 depletion did not significantly alter the size of the tumors but accelerated acinar-ductal metaplasia. These results demonstrate that Snail1 is expressed in PMCs and plays a pivotal role in maintaining acinar cells within the pancreas in normal and pathological conditions. PMID:26735179

  8. Mechanisms of Cell Death in Acute Liver Failure

    PubMed Central

    Bantel, Heike; Schulze-Osthoff, Klaus

    2012-01-01

    Acute liver failure (ALF) can be the consequence of various etiologies, that might vary between different geographic regions. Most frequent are intoxications with acetaminophen, viral hepatitis, or liver damage of unknown origin. ALF occurs when the extent of hepatocyte death exceeds the regenerative capacity of the liver. The mode of liver cell death that is predominantly induced in ALF, i.e., apoptosis or necrosis, is still controversial and presumably determined by the etiology, duration, and magnitude of liver injury. Severe liver damage involves oxidative stress and depletion of ATP resulting in necrosis. In contrast, maintenance of ATP stores is required for the execution of apoptosis. Recent data suggest that necrosis resulting from severe liver damage is associated with poor outcome of ALF patients. Discrimination between apoptosis and necrosis might be therefore useful for the identification of ALF patients requiring liver transplantation. Identification of the molecular cell death mechanisms remains an important issue not only for early prediction of ALF outcome, but also for therapeutic interventions. In view of the pleiotropic functions of critical mediators of cell death and tissue regeneration, a particular challenge will be to reduce hepatocellular death without inhibiting the regenerative capacity of the liver. Here, we review the molecular mechanisms of hepatocyte injury and the pathways leading to apoptosis and necrosis, which might represent potential diagnostic and therapeutic targets in ALF. PMID:22485095

  9. Lipid raft involvement in yeast cell growth and death.

    PubMed

    Mollinedo, Faustino

    2012-01-01

    The notion that cellular membranes contain distinct microdomains, acting as scaffolds for signal transduction processes, has gained considerable momentum. In particular, a class of such domains that is rich in sphingolipids and cholesterol, termed as lipid rafts, is thought to compartmentalize the plasma membrane, and to have important roles in survival and cell death signaling in mammalian cells. Likewise, yeast lipid rafts are membrane domains enriched in sphingolipids and ergosterol, the yeast counterpart of mammalian cholesterol. Sterol-rich membrane domains have been identified in several fungal species, including the budding yeast Saccharomyces cerevisiae, the fission yeast Schizosaccharomyces pombe as well as the pathogens Candida albicans and Cryptococcus neoformans. Yeast rafts have been mainly involved in membrane trafficking, but increasing evidence implicates rafts in a wide range of additional cellular processes. Yeast lipid rafts house biologically important proteins involved in the proper function of yeast, such as proteins that control Na(+), K(+), and pH homeostasis, which influence many cellular processes, including cell growth and death. Membrane raft constituents affect drug susceptibility, and drugs interacting with sterols alter raft composition and membrane integrity, leading to yeast cell death. Because of the genetic tractability of yeast, analysis of yeast rafts could be an excellent model to approach unanswered questions of mammalian raft biology, and to understand the role of lipid rafts in the regulation of cell death and survival in human cells. A better insight in raft biology might lead to envisage new raft-mediated approaches to the treatment of human diseases where regulation of cell death and survival is critical, such as cancer and neurodegenerative diseases.

  10. Lipid raft involvement in yeast cell growth and death

    PubMed Central

    Mollinedo, Faustino

    2012-01-01

    The notion that cellular membranes contain distinct microdomains, acting as scaffolds for signal transduction processes, has gained considerable momentum. In particular, a class of such domains that is rich in sphingolipids and cholesterol, termed as lipid rafts, is thought to compartmentalize the plasma membrane, and to have important roles in survival and cell death signaling in mammalian cells. Likewise, yeast lipid rafts are membrane domains enriched in sphingolipids and ergosterol, the yeast counterpart of mammalian cholesterol. Sterol-rich membrane domains have been identified in several fungal species, including the budding yeast Saccharomyces cerevisiae, the fission yeast Schizosaccharomyces pombe as well as the pathogens Candida albicans and Cryptococcus neoformans. Yeast rafts have been mainly involved in membrane trafficking, but increasing evidence implicates rafts in a wide range of additional cellular processes. Yeast lipid rafts house biologically important proteins involved in the proper function of yeast, such as proteins that control Na+, K+, and pH homeostasis, which influence many cellular processes, including cell growth and death. Membrane raft constituents affect drug susceptibility, and drugs interacting with sterols alter raft composition and membrane integrity, leading to yeast cell death. Because of the genetic tractability of yeast, analysis of yeast rafts could be an excellent model to approach unanswered questions of mammalian raft biology, and to understand the role of lipid rafts in the regulation of cell death and survival in human cells. A better insight in raft biology might lead to envisage new raft-mediated approaches to the treatment of human diseases where regulation of cell death and survival is critical, such as cancer and neurodegenerative diseases. PMID:23087902

  11. Autophagonizer, a novel synthetic small molecule, induces autophagic cell death

    SciTech Connect

    Choi, In-Kwon; Cho, Yoon Sun; Jung, Hye Jin; Kwon, Ho Jeong

    2010-03-19

    Autophagy is an apoptosis-independent mechanism of cell death that protects the cell from environmental imbalances and infection by pathogens. We identified a novel small molecule, 2-(3-Benzyl-4-oxo-3,4,5,6,7,8-hexahydro-benzo[4,5]thieno[2,3-d] pyrimidin-2-ylsulfanylmethyl)-oxazole-4-carboxylic acid (2-pyrrolidin-1-yl-ethyl)-amide (referred as autophagonizer), using high-content cell-based screening and the autophagosome marker EGFP-LC3. Autophagonizer inhibited growth and induced cell death in the human tumor cell lines MCF7, HeLa, HCT116, A549, AGS, and HT1080 via a caspase-independent pathway. Conversion of cytosolic LC3-I to autophagosome-associated LC3-II was greatly enhanced by autophagonizer treatment. Transmission electron microscopy and acridine orange staining revealed increased autophagy in the cytoplasm of autophagonizer-treated cells. In conclusion, autophagonizer is a novel autophagy inducer with unique structure, which induces autophagic cell death in the human tumor cell lines.

  12. The metabolism beyond programmed cell death in yeast

    PubMed Central

    Ring, Julia; Sommer, Cornelia; Carmona-Gutierrez, Didac; Ruckenstuhl, Christoph; Eisenberg, Tobias; Madeo, Frank

    2012-01-01

    A cell's reaction to any change in the endogenous or exogenous conditions often involves a complex response that eventually either leads to cell adaptation and survival or to the initiation and execution of (programmed) cell death. The molecular decision whether to live or die, while depending on a cell's genome, is fundamentally influenced by its actual metabolic status. Thus, the collection of all metabolites present in a biological system at a certain time point (the so-called metabolome) defines its physiological, developmental and pathological state and determines its fate during changing and stressful conditions. The budding yeast Saccharomyces cerevisiae is a unicellular organism that allows to easily modify and monitor conditions affecting the cell's metabolome, for instance through a simple change of the nutrition source. Such changes can be used to mimic and study (patho)physiological scenarios, including caloric restriction and longevity, the Warburg effect in cancer cells or changes in mitochondrial mass affecting cell death. In addition, disruption of single genes or generation of respiratory deficiency (via abrogation of mitochondrial DNA) assists in revealing connections between metabolism and apoptosis. In this minireview, we discuss recent studies using the potential of the yeast model to provide new insights into the processes of stress defense, cell death and longevity. PMID:22480867

  13. Ghrelin Inhibits Oligodendrocyte Cell Death by Attenuating Microglial Activation

    PubMed Central

    Lee, Jee Youn

    2014-01-01

    Background Recently, we reported the antiapoptotic effect of ghrelin in spinal cord injury-induced apoptotic cell death of oligodendrocytes. However, how ghrelin inhibits oligodendrocytes apoptosis, is still unknown. Therefore, in the present study, we examined whether ghrelin inhibits microglia activation and thereby inhibits oligodendrocyte apoptosis. Methods Using total cell extracts prepared from BV-2 cells activated by lipopolysaccharide (LPS) with or without ghrelin, the levels of p-p38 phosphor-p38 mitogen-activated protein kinase (p-p38MAPK), phospho-c-Jun N-terminal kinase (pJNK), p-c-Jun, and pro-nerve growth factor (proNGF) were examined by Western blot analysis. Reactive oxygen species (ROS) production was investigated by using dichlorodihydrofluorescein diacetate. To examine the effect of ghrelin on oligodendrocyte cell death, oligodendrocytes were cocultured in transwell chambers of 24-well plates with LPS-stimulated BV-2 cells. After 48 hours incubation, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay and terminal deoxynucleotidyl transferase 2'-deoxyuridine, 5'-triphosphate nick end labeling staining were assessed. Results Ghrelin treatment significantly decreased levels of p-p38MAPK, p-JNK, p-c-Jun, and proNGF in LPS-stimulated BV-2 cells. ROS production increased in LPS-stimulated BV-2 cells was also significantly inhibited by ghrelin treatment. In addition, ghrelin significantly inhibited oligodendrocyte cell death when cocultured with LPS-stimulated BV-2 cells. Conclusion Ghrelin inhibits oligodendrocyte cell death by decreasing proNGF and ROS production as well as p38MAPK and JNK activation in activated microglia as an anti-inflammatory hormone. PMID:25309797

  14. Measuring Cell Death by Trypan Blue Uptake and Light Microscopy.

    PubMed

    Crowley, Lisa C; Marfell, Brooke J; Christensen, Melinda E; Waterhouse, Nigel J

    2016-01-01

    Trypan blue is a colorimetric dye that stains dead cells with a blue color easily observed using light microscopy at low resolution. The staining procedure is rapid and cells can be analyzed within minutes. The number of live (unstained) and dead (blue) cells can be counted using a hemocytometer on a basic upright microscope. Trypan blue staining is therefore a convenient assay for rapidly determining the overall viability of cells in a culture before commencing scientific experimentation, or for quantitating cell death following treatment with any cytotoxic stimuli. PMID:27371594

  15. Curcumin Attenuates Staurosporine-Mediated Death of Retinal Ganglion Cells

    PubMed Central

    Burugula, Balabharathi; Ganesh, Bhagyalaxmi S.

    2011-01-01

    Purpose. Staurosporine (SS) causes retinal ganglion cell (RGC) death in vivo, but the underlying mechanisms have been unclear. Since previous studies on RGC-5 cells indicated that SS induces cell death by elevating proteases, this study was undertaken to investigate whether SS induces RGC loss by elevating proteases in the retina, and curcumin prevents SS-mediated death of RGCs. Methods. Transformed mouse retinal ganglion-like cells (RGC-5) were treated with 2.0 μM SS and various doses of curcumin. Two optimal doses of SS (12.5 and 100 nM) and curcumin (2.5 and 10 μM) were injected into the vitreous of C57BL/6 mice. Matrix metalloproteinase (MMP)-9, tissue plasminogen activator (tPA), and urokinase plasminogen activator (uPA) activities were assessed by zymography assays. Viability of RGC-5 cells was assessed by MTT assays. RGC and amacrine cell loss in vivo was assessed by immunostaining with Brn3a and ChAT antibodies, respectively. Frozen retinal cross sections were immunostained for nuclear factor-κB (NF-κB). Results. Staurosporine induced uPA and tPA levels in RGC-5 cells, and MMP-9, uPA, and tPA levels in the retinas and promoted the death of RGC-5 cells in vitro and RGCs and amacrine cells in vivo. In contrast, curcumin attenuated RGC and amacrine cell loss, despite elevated levels of proteases. An NF-κB inhibitory peptide reversed curcumin-mediated protective effect on RGC-5 cells, but did not inhibit protease levels. Curcumin did not inhibit protease levels in vivo, but attenuated RGC and amacrine cell loss by restoring NF-κB expression. Conclusions. The results show that curcumin attenuates RGC and amacrine cell death despite elevated levels of proteases and raises the possibility that it may be used as a plausible adjuvant therapeutic agent to prevent the loss of these cells in retinal degenerative conditions. PMID:21498608

  16. Cell death monitoring using quantitative optical coherence tomography methods

    NASA Astrophysics Data System (ADS)

    Farhat, Golnaz; Yang, Victor X. D.; Kolios, Michael C.; Czarnota, Gregory J.

    2011-03-01

    Cell death is characterized by a series of predictable morphological changes, which modify the light scattering properties of cells. We present a multi-parametric approach to detecting changes in subcellular morphology related to cell death using optical coherence tomography (OCT). Optical coherence tomography data were acquired from acute myeloid leukemia (AML) cells undergoing apoptosis over a period of 48 hours. Integrated backscatter (IB) and spectral slope (SS) were computed from OCT backscatter spectra and statistical parameters were extracted from a generalized gamma (GG) distribution fit to OCT signal intensity histograms. The IB increased by 2-fold over 48 hours with significant increases observed as early as 4 hours. The SS increased in steepness by 2.5-fold with significant changes at 12 hours, while the GG parameters were sensitive to apoptotic changes at 24 to 48 hours. Histology slides indicated nuclear condensation and fragmentation at 24 hours, suggesting the late scattering changes could be related to nuclear structure. A second series of measurements from AML cells treated with cisplatin, colchicine or ionizing radiation suggested that the GG parameters could potentially differentiate between modes of cell death. Distinct cellular morphology was observed in histology slides obtained from cells treated under each condition.

  17. Evidence of apoptotic cell death in HIV encephalitis.

    PubMed Central

    Petito, C. K.; Roberts, B.

    1995-01-01

    The mechanism of cell death in the brains of patients with acquired immune deficiency syndrome was examined in 15 cases, 8 of whom had human immunodeficiency virus (HIV) encephalitis, and in 8 control cases. Postmortem formalin-fixed, paraffin-embedded sections were prepared for routine histology and immunohistochemistry to detect cell-specific antigens. Apoptosis was detected by its morphology and by in situ end labeling of its characteristic oligonucleosomal fragments. Combined in situ end labeling and immunohistochemistry identified specific cell types. Six acquired immune deficiency syndrome brains, 5 of which had HIV encephalitis, contained positive nuclei by in situ end labeling. Co-labeling studies identified the cells as neurons, reactive astrocytes, and, rarely, the multinucleated giant cells of HIV encephalitis. The only control with nuclei positive by in situ end labeling had hepatic encephalopathy and Alzheimer type II astrocytes; the location and absence of cell-specific markers suggested a glial origin for the labeled cells. These results demonstrate that at least some neuronal and astrocytic death in HIV infection occurs by apoptosis. Its stimuli are unknown, but likely candidates include tumor necrosis factor or HIV viral products. Additionally, we hypothesize that apoptotic death of reactive astrocytes may be a normal mechanism whereby the brain removes an excess number of astrocytes that have proliferated after certain types of brain injury. Images Figure 1 Figure 2 Figure 3 Figure 5 Figure 4 PMID:7747806

  18. Calcium and cell death signaling in neurodegeneration and aging.

    PubMed

    Smaili, Soraya; Hirata, Hanako; Ureshino, Rodrigo; Monteforte, Priscila T; Morales, Ana P; Muler, Mari L; Terashima, Juliana; Oseki, Karen; Rosenstock, Tatiana R; Lopes, Guiomar S; Bincoletto, Claudia

    2009-09-01

    Transient increase in cytosolic (Cac2+) and mitochondrial Ca2+ (Ca m2+) are essential elements in the control of many physiological processes. However, sustained increases in Ca c2+ and Ca m2+ may contribute to oxidative stress and cell death. Several events are related to the increase in Ca m2+, including regulation and activation of a number of Ca2+ dependent enzymes, such as phospholipases, proteases and nucleases. Mitochondria and endoplasmic reticulum (ER) play pivotal roles in the maintenance of intracellular Ca2+ homeostasis and regulation of cell death. Several lines of evidence have shown that, in the presence of some apoptotic stimuli, the activation of mitochondrial processes may lead to the release of cytochrome c followed by the activation of caspases, nuclear fragmentation and apoptotic cell death. The aim of this review was to show how changes in calcium signaling can be related to the apoptotic cell death induction. Calcium homeostasis was also shown to be an important mechanism involved in neurodegenerative and aging processes.

  19. Light uncages a copper complex to induce nonapoptotic cell death.

    PubMed

    Kumbhar, Anupa A; Franks, Andrew T; Butcher, Raymond J; Franz, Katherine J

    2013-03-25

    Cu3G is a Cu(II) complex of a photoactive tetradentate ligand that is cleaved upon UV irradiation to release Cu. Here we show that the cytotoxicity of Cu3G increases in response to brief UV stimulation to result in extensive cytoplasmic vacuolization that is indicative of nonapoptotic cell death. PMID:23417227

  20. Hox proteins: sculpting body parts by activating localized cell death.

    PubMed

    Alonso, Claudio R

    2002-11-19

    Hox proteins shape animal structures by eliciting different developmental programs along the anteroposterior body axis. A recent study reveals that the Drosophila Hox protein Deformed directly activates the cell-death-promoting gene reaper to maintain the boundaries between distinct head segments.

  1. Bortezomib induces autophagic death in proliferating human endothelial cells

    SciTech Connect

    Belloni, Daniela; Veschini, Lorenzo; Foglieni, Chiara; Dell'Antonio, Giacomo; Caligaris-Cappio, Federico; Ferrarini, Marina; Ferrero, Elisabetta

    2010-04-01

    The proteasome inhibitor Bortezomib has been approved for the treatment of relapsed/refractory multiple myeloma (MM), thanks to its ability to induce MM cell apoptosis. Moreover, Bortezomib has antiangiogenic properties. We report that endothelial cells (EC) exposed to Bortezomib undergo death to an extent that depends strictly on their activation state. Indeed, while quiescent EC are resistant to Bortezomib, the drug results maximally toxic in EC switched toward angiogenesis with FGF, and exerts a moderate effect on subconfluent HUVEC. Moreover, EC activation state deeply influences the death pathway elicited by Bortezomib: after treatment, angiogenesis-triggered EC display typical features of apoptosis. Conversely, death of subconfluent EC is preceded by ROS generation and signs typical of autophagy, including intense cytoplasmic vacuolization with evidence of autophagosomes at electron microscopy, and conversion of the cytosolic MAP LC3 I form toward the autophagosome-associated LC3 II form. Treatment with the specific autophagy inhibitor 3-MA prevents both LC3 I/LC3 II conversion and HUVEC cell death. Finally, early removal of Bortezomib is accompanied by the recovery of cell shape and viability. These findings strongly suggest that Bortezomib induces either apoptosis or autophagy in EC; interfering with the autophagic response may potentiate the antiangiogenic effect of the drug.

  2. Mitochondrial and Cell Death Mechanisms in Neurodegenerative Diseases

    PubMed Central

    Martin, Lee J.

    2010-01-01

    Alzheimer’s disease (AD), Parkinson’s disease (PD) and amyotrophic lateral sclerosis (ALS) are the most common human adult-onset neurodegenerative diseases. They are characterized by prominent age-related neurodegeneration in selectively vulnerable neural systems. Some forms of AD, PD, and ALS are inherited, and genes causing these diseases have been identified. Nevertheless, the mechanisms of the neuronal cell death are unresolved. Morphological, biochemical, genetic, as well as cell and animal model studies reveal that mitochondria could have roles in this neurodegeneration. The functions and properties of mitochondria might render subsets of selectively vulnerable neurons intrinsically susceptible to cellular aging and stress and overlying genetic variations, triggering neurodegeneration according to a cell death matrix theory. In AD, alterations in enzymes involved in oxidative phosphorylation, oxidative damage, and mitochondrial binding of Aβ and amyloid precursor protein have been reported. In PD, mutations in putative mitochondrial proteins have been identified and mitochondrial DNA mutations have been found in neurons in the substantia nigra. In ALS, changes occur in mitochondrial respiratory chain enzymes and mitochondrial cell death proteins. Transgenic mouse models of human neurodegenerative disease are beginning to reveal possible principles governing the biology of selective neuronal vulnerability that implicate mitochondria and the mitochondrial permeability transition pore. This review summarizes how mitochondrial pathobiology might contribute to neuronal death in AD, PD, and ALS and could serve as a target for drug therapy. PMID:21258649

  3. PROGRAMMED CELL DEATH IN EXTRAOCULAR MUSCLE TENDON/SCLERA PRECURSORS

    EPA Science Inventory

    Abstract

    Purpose: This study was designed to examine the occurrence of natural cell death in the periocular mesenchyme of mouse embryos.

    Methods: Vital staining with LysoTracker Red and Nile blue sulphate as well as terminal nick end labeling (TUNEL) were utiliz...

  4. Targeting Mitochondria with Avocatin B Induces Selective Leukemia Cell Death.

    PubMed

    Lee, Eric A; Angka, Leonard; Rota, Sarah-Grace; Hanlon, Thomas; Mitchell, Andrew; Hurren, Rose; Wang, Xiao Ming; Gronda, Marcela; Boyaci, Ezel; Bojko, Barbara; Minden, Mark; Sriskanthadevan, Shrivani; Datti, Alessandro; Wrana, Jeffery L; Edginton, Andrea; Pawliszyn, Janusz; Joseph, Jamie W; Quadrilatero, Joe; Schimmer, Aaron D; Spagnuolo, Paul A

    2015-06-15

    Treatment regimens for acute myeloid leukemia (AML) continue to offer weak clinical outcomes. Through a high-throughput cell-based screen, we identified avocatin B, a lipid derived from avocado fruit, as a novel compound with cytotoxic activity in AML. Avocatin B reduced human primary AML cell viability without effect on normal peripheral blood stem cells. Functional stem cell assays demonstrated selectivity toward AML progenitor and stem cells without effects on normal hematopoietic stem cells. Mechanistic investigations indicated that cytotoxicity relied on mitochondrial localization, as cells lacking functional mitochondria or CPT1, the enzyme that facilitates mitochondria lipid transport, were insensitive to avocatin B. Furthermore, avocatin B inhibited fatty acid oxidation and decreased NADPH levels, resulting in ROS-dependent leukemia cell death characterized by the release of mitochondrial proteins, apoptosis-inducing factor, and cytochrome c. This study reveals a novel strategy for selective leukemia cell eradication based on a specific difference in mitochondrial function. PMID:26077472

  5. Metal-accelerated oxidation in plant cell death

    SciTech Connect

    Czuba, M. )

    1993-05-01

    Cadmium and mercury toxicity is further enhanced by external oxidizing conditions O[sub 3] or inherent plant processes. Lepidium sativum L, Lycopersicon esculentum Mill., or Phaseolus vulgaris L, were grown inpeat-lite to maturity under continuous cadmium exposure followed by one oxidant (O[sub 3]-6 hr. 30 pphm) exposure, with or without foliar calcium pretreatments. In comparison, Daucus carota, L and other species grown in a 71-V suspension, with or without 2,4-D were exposed continuously to low levels of methylmercury during exponential growth and analyzed in aggregates of distinct populations. Proteins were extracted and analyzed. Mechanisms of toxicity and eventual cell death are Ca-mediated and involve chloroplast, stomatal-water relations and changes in oxidant-anti-oxidant components in cells. Whether the metal-accelerated oxidative damage proceeds to cell death, depends on the species and its differential biotransformation system and cell association component.

  6. Autophagy and Tubular Cell Death in the Kidney.

    PubMed

    Havasi, Andrea; Dong, Zheng

    2016-05-01

    Many common renal insults such as ischemia and toxic injury primarily target the tubular epithelial cells, especially the highly metabolically active proximal tubular segment. Tubular epithelial cells are particularly dependent on autophagy to maintain homeostasis and respond to stressors. The pattern of autophagy in the kidney has a unique spatial and chronologic signature. Recent evidence has shown that there is complex cross-talk between autophagy and various cell death pathways. This review specifically discusses the interplay between autophagy and cell death in the renal tubular epithelia. It is imperative to review this topic because recent discoveries have improved our mechanistic understanding of the autophagic process and have highlighted its broad clinical applications, making autophagy a major target for drug development. PMID:27339383

  7. Ceramide Synthase-dependent Ceramide Generation and Programmed Cell Death

    PubMed Central

    Mullen, Thomas D.; Jenkins, Russell W.; Clarke, Christopher J.; Bielawski, Jacek; Hannun, Yusuf A.; Obeid, Lina M.

    2011-01-01

    The sphingolipid ceramide has been widely implicated in the regulation of programmed cell death or apoptosis. The accumulation of ceramide has been demonstrated in a wide variety of experimental models of apoptosis and in response to a myriad of stimuli and cellular stresses. However, the detailed mechanisms of its generation and regulatory role during apoptosis are poorly understood. We sought to determine the regulation and roles of ceramide production in a model of ultraviolet light-C (UV-C)-induced programmed cell death. We found that UV-C irradiation induces the accumulation of multiple sphingolipid species including ceramide, dihydroceramide, sphingomyelin, and hexosylceramide. Late ceramide generation was also found to be regulated by Bcl-xL, Bak, and caspases. Surprisingly, inhibition of de novo synthesis using myriocin or fumonisin B1 resulted in decreased overall cellular ceramide levels basally and in response to UV-C, but only fumonisin B1 inhibited cell death, suggesting the presence of a ceramide synthase (CerS)-dependent, sphingosine-derived pool of ceramide in regulating programmed cell death. We found that this pool did not regulate the mitochondrial pathway, but it did partially regulate activation of caspase-7 and, more importantly, was necessary for late plasma membrane permeabilization. Attempting to identify the CerS responsible for this effect, we found that combined knockdown of CerS5 and CerS6 was able to decrease long-chain ceramide accumulation and plasma membrane permeabilization. These data identify a novel role for CerS and the sphingosine salvage pathway in regulating membrane permeability in the execution phase of programmed cell death. PMID:21388949

  8. Anoikis: a necessary death program for anchorage-dependent cells.

    PubMed

    Chiarugi, Paola; Giannoni, Elisa

    2008-12-01

    Cell to matrix adhesion is a key factor for cellular homeostasis and disruption of such interaction has adverse effects on cell survival. It leads to a specific type of apoptosis known as "anoikis" in most non-transformed cell types. This kind of apoptosis following loss of cell anchorage is important for development, tissue homeostasis and several diseases. Integrins sense mechanical forces arising from the matrix, thereby converting these stimuli to downstream signals modulating cell viability. Anchorage-independent growth is a crucial step during tumorigenesis and in particular during the metastatic spreading of cancer cells. The disruption of the tight control leading an "homeless" cell to death is therefore able to violate the cell defences against transformation. This review analyses the recent investigations into the molecular mechanisms governing anoikis, discussing the different ways in which adhesion can influence this process and addressing the relevance of this unique apoptosis mode in the development of metastatic cancers, as well as in other diseases.

  9. Imipramine protects mouse hippocampus against tunicamycin-induced cell death.

    PubMed

    Ono, Yoko; Shimazawa, Masamitsu; Ishisaka, Mitsue; Oyagi, Atsushi; Tsuruma, Kazuhiro; Hara, Hideaki

    2012-12-01

    Endoplasmic reticulum (ER) stress is implicated in various diseases. Recently, some reports have suggested that the sigma-1 receptor may play a role in ER stress, and many antidepressants have a high affinity for the sigma-1 receptor. In the present study, we focused on imipramine, a widely used antidepressant, and investigated whether it might protect against the neuronal cell death induced by tunicamycin, an ER stress inducer. In mouse cultured hippocampal HT22 cells, imipramine inhibited cell death and caspase-3 activation induced by tunicamycin, although it did not alter the elevated expressions of 78 kDa glucose-regulated protein (GRP78) and C/EBP-homologous protein (CHOP). Interestingly, in such cells application of imipramine normalized the expression of the sigma-1 receptor, which was decreased by treatment with tunicamycin alone. Additionally, NE-100, a selective sigma-1 receptor antagonist, abolished the protective effect of imipramine against such tunicamycin-induced cell death. Imipramine inhibited the reduction of mitochondrial membrane potential induced by tunicamycin, and NE-100 blocked this modulating effect of imipramine. Furthermore, in anesthetized mice intracerebroventricular administration of tunicamycin decreased the number of neuronal cells in the hippocampus, particularly in the CA1 and dentate gyrus (DG) areas, and 7 days' imipramine treatment (10mg/kg/day; i.p.) significantly suppressed these reductions in CA1 and DG. These findings suggest that imipramine protects against ER stress-induced hippocampal neuronal cell death both in vitro and in vivo. Such protection may be partly due to the sigma-1 receptor.

  10. A Conserved Core of Programmed Cell Death Indicator Genes Discriminates Developmentally and Environmentally Induced Programmed Cell Death in Plants.

    PubMed

    Olvera-Carrillo, Yadira; Van Bel, Michiel; Van Hautegem, Tom; Fendrych, Matyáš; Huysmans, Marlies; Simaskova, Maria; van Durme, Matthias; Buscaill, Pierre; Rivas, Susana; S Coll, Nuria; Coppens, Frederik; Maere, Steven; Nowack, Moritz K

    2015-12-01

    A plethora of diverse programmed cell death (PCD) processes has been described in living organisms. In animals and plants, different forms of PCD play crucial roles in development, immunity, and responses to the environment. While the molecular control of some animal PCD forms such as apoptosis is known in great detail, we still know comparatively little about the regulation of the diverse types of plant PCD. In part, this deficiency in molecular understanding is caused by the lack of reliable reporters to detect PCD processes. Here, we addressed this issue by using a combination of bioinformatics approaches to identify commonly regulated genes during diverse plant PCD processes in Arabidopsis (Arabidopsis thaliana). Our results indicate that the transcriptional signatures of developmentally controlled cell death are largely distinct from the ones associated with environmentally induced cell death. Moreover, different cases of developmental PCD share a set of cell death-associated genes. Most of these genes are evolutionary conserved within the green plant lineage, arguing for an evolutionary conserved core machinery of developmental PCD. Based on this information, we established an array of specific promoter-reporter lines for developmental PCD in Arabidopsis. These PCD indicators represent a powerful resource that can be used in addition to established morphological and biochemical methods to detect and analyze PCD processes in vivo and in planta.

  11. Blockade of maitotoxin-induced oncotic cell death reveals zeiosis

    PubMed Central

    Estacion, Mark; Schilling, William P

    2002-01-01

    Background Maitotoxin (MTX) initiates cell death by sequentially activating 1) Ca2+ influx via non-selective cation channels, 2) uptake of vital dyes via formation of large pores, and 3) release of lactate dehydrogenase, an indication of cell lysis. MTX also causes formation of membrane blebs, which dramatically dilate during the cytolysis phase. To determine the role of phospholipase C (PLC) in the cell death cascade, U73122, a specific inhibitor of PLC, and U73343, an inactive analog, were examined on MTX-induced responses in bovine aortic endothelial cells. Results Addition of either U73122 or U73343, prior to MTX, produced a concentration-dependent inhibition of the cell death cascade (IC50 ≈ 1.9 and 0.66 μM, respectively) suggesting that the effect of these agents was independent of PLC. Addition of U73343 shortly after MTX, prevented or attenuated the effects of the toxin, but addition at later times had little or no effect. Time-lapse videomicroscopy showed that U73343 dramatically altered the blebbing profile of MTX-treated cells. Specifically, U73343 blocked bleb dilation and converted the initial blebbing event into "zeiosis", a type of membrane blebbing commonly associated with apoptosis. Cells challenged with MTX and rescued by subsequent addition of U73343, showed enhanced caspase-3 activity 48 hr after the initial insult, consistent with activation of the apoptotic program. Conclusions Within minutes of MTX addition, endothelial cells die by oncosis. Rescue by addition of U73343 shortly after MTX showed that a small percentage of cells are destined to die by oncosis, but that a larger percentage survive; cells that survive the initial insult exhibit zeiosis and may ultimately die by apoptotic mechanisms. PMID:11825342

  12. Lead-induced cell death in testes of young rats.

    PubMed

    Adhikari, N; Sinha, N; Narayan, R; Saxena, D K

    2001-01-01

    Lead is a well-documented testicular toxicant. The present work was planned to study the occurrence of germ cell death after lead administration. Young growing rats were treated with 5, 10 and 20 mg kg(-1) body weight of lead for 2 weeks. Cell death was assessed by employing in situ TUNEL staining, DNA electrophoresis and morphological examination of the tubules. The results showed that Pb induced significant numbers of germ cells to undergo apoptosis in the seminiferous tubules of rats treated with 20 mg kg(-1) body weight. However, DNA fragmentation was not detected at any of the doses. The level of lead accumulation in the testis increased in a dose-dependent manner. PMID:11481659

  13. Glycosphingolipids and cell death: One aim, many ways

    PubMed Central

    Garcia-Ruiz, Carmen; Morales, Albert; Fernández-Checa, José C.

    2015-01-01

    Glycosphingolipids (GSLs) are a family of bioactive lipids that in addition to their role in the regulation of structural properties of membrane bilayers have emerged as crucial players in many biological processes and signal transduction pathways. Rather than being uniformly distributed within membrane bilayers, GSLs are localized in selective domains called lipid rafts where many signaling platforms operate. One of the most important functions of GSLs, particularly ceramide, is their ability to regulate cell death pathways and hence cell fate. This complex role is accomplished by the ability of GSLs to act in distinct subcellular strategic centers, such as mitochondria, endoplasmic reticulum (ER) or lysosomes to mediate apoptosis, ER stress, autophagy, lysosomal membrane permeabilization and necroptosis. Hence better understanding the role of GSLs in cell death may be of relevance for a number of pathological processes and diseases, including neurodegeneration, metabolic liver diseases and cancer. PMID:25637183

  14. Molecular and Translational Classifications of DAMPs in Immunogenic Cell Death

    PubMed Central

    Garg, Abhishek D.; Galluzzi, Lorenzo; Apetoh, Lionel; Baert, Thais; Birge, Raymond B.; Bravo-San Pedro, José Manuel; Breckpot, Karine; Brough, David; Chaurio, Ricardo; Cirone, Mara; Coosemans, An; Coulie, Pierre G.; De Ruysscher, Dirk; Dini, Luciana; de Witte, Peter; Dudek-Peric, Aleksandra M.; Faggioni, Alberto; Fucikova, Jitka; Gaipl, Udo S.; Golab, Jakub; Gougeon, Marie-Lise; Hamblin, Michael R.; Hemminki, Akseli; Herrmann, Martin; Hodge, James W.; Kepp, Oliver; Kroemer, Guido; Krysko, Dmitri V.; Land, Walter G.; Madeo, Frank; Manfredi, Angelo A.; Mattarollo, Stephen R.; Maueroder, Christian; Merendino, Nicolò; Multhoff, Gabriele; Pabst, Thomas; Ricci, Jean-Ehrland; Riganti, Chiara; Romano, Erminia; Rufo, Nicole; Smyth, Mark J.; Sonnemann, Jürgen; Spisek, Radek; Stagg, John; Vacchelli, Erika; Vandenabeele, Peter; Vandenberk, Lien; Van den Eynde, Benoit J.; Van Gool, Stefaan; Velotti, Francesca; Zitvogel, Laurence; Agostinis, Patrizia

    2015-01-01

    The immunogenicity of malignant cells has recently been acknowledged as a critical determinant of efficacy in cancer therapy. Thus, besides developing direct immunostimulatory regimens, including dendritic cell-based vaccines, checkpoint-blocking therapies, and adoptive T-cell transfer, researchers have started to focus on the overall immunobiology of neoplastic cells. It is now clear that cancer cells can succumb to some anticancer therapies by undergoing a peculiar form of cell death that is characterized by an increased immunogenic potential, owing to the emission of the so-called “damage-associated molecular patterns” (DAMPs). The emission of DAMPs and other immunostimulatory factors by cells succumbing to immunogenic cell death (ICD) favors the establishment of a productive interface with the immune system. This results in the elicitation of tumor-targeting immune responses associated with the elimination of residual, treatment-resistant cancer cells, as well as with the establishment of immunological memory. Although ICD has been characterized with increased precision since its discovery, several questions remain to be addressed. Here, we summarize and tabulate the main molecular, immunological, preclinical, and clinical aspects of ICD, in an attempt to capture the essence of this phenomenon, and identify future challenges for this rapidly expanding field of investigation. PMID:26635802

  15. Aquatic viruses induce host cell death pathways and its application.

    PubMed

    Reshi, Latif; Wu, Jen-Leih; Wang, Hao-Ven; Hong, Jiann-Ruey

    2016-01-01

    Virus infections of mammalian and animal cells consist of a series of events. As intracellular parasites, viruses rely on the use of host cellular machinery. Through the use of cell culture and molecular approaches over the past decade, our knowledge of the biology of aquatic viruses has grown exponentially. The increase in aquaculture operations worldwide has provided new approaches for the transmission of aquatic viruses that include RNA and DNA viruses. Therefore, the struggle between the virus and the host for control of the cell's death machinery is crucial for survival. Viruses are obligatory intracellular parasites and, as such, must modulate apoptotic pathways to control the lifespan of their host to complete their replication cycle. This paper updates the discussion on the detailed mechanisms of action that various aquatic viruses use to induce cell death pathways in the host, such as Bad-mediated, mitochondria-mediated, ROS-mediated and Fas-mediated cell death circuits. Understanding how viruses exploit the apoptotic pathways of their hosts may provide great opportunities for the development of future potential therapeutic strategies and pathogenic insights into different aquatic viral diseases.

  16. Methylglyoxal induces mitochondrial dysfunction and cell death in liver.

    PubMed

    Seo, Kyuhwa; Ki, Sung Hwan; Shin, Sang Mi

    2014-09-01

    Degradation of glucose is aberrantly increased in hyperglycemia, which causes various harmful effects on the liver. Methylglyoxal is produced during glucose degradation and the levels of methylglyoxal are increased in diabetes patients. In this study we investigated whether methylglyoxal induces mitochondrial impairment and apoptosis in HepG2 cells and induces liver toxicity in vivo. Methylglyoxal caused apoptotic cell death in HepG2 cells. Moreover, methylglyoxal significantly promoted the production of reactive oxygen species (ROS) and depleted glutathione (GSH) content. Pretreatment with antioxidants caused a marked decrease in methylglyoxal-induced apoptosis, indicating that oxidant species are involved in the apoptotic process. Methylglyoxal treatment induced mitochondrial permeability transition, which represents mitochondrial impairment. However, pretreatment with cyclosporin A, an inhibitor of the formation of the permeability transition pore, partially inhibited methylglyoxal-induced cell death. Furthermore, acute treatment of mice with methylglyoxal increased the plasma levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST), indicating liver toxicity. Collectively, our results showed that methylglyoxal increases cell death and induces liver toxicity, which results from ROS-mediated mitochondrial dysfunction and oxidative stress. PMID:25343013

  17. Megasporogenesis and programmed cell death in Tillandsia (Bromeliaceae).

    PubMed

    Papini, Alessio; Mosti, Stefano; Milocani, Eva; Tani, Gabriele; Di Falco, Pietro; Brighigna, Luigi

    2011-10-01

    The degeneration of three of four meiotic products is a very common process in the female gender of oogamous eukaryotes. In Tillandsia (and many other angiosperms), the surviving megaspore has a callose-free wall in chalazal position while the other three megaspores are completely embedded in callose. Therefore, nutrients and signals can reach more easily the functional megaspore from the nucellus through the chalazal pole with respect to the other megaspores. The abortion of three of four megaspores was already recognized as the result of a programmed cell death (PCD) process. We investigated the process to understand the modality of this specific type of PCD and its relationship to the asymmetric callose deposition around the tetrad. The decision on which of the four megaspores will be the supernumerary megaspores in angiosperms, and hence destined to undergo programmed cell death, appears to be linked to the callose layer deposition around the tetrad. During supernumerary megaspores degeneration, events leading to the deletion of the cells do not appear to belong to a single type of cell death. The first morphological signs are typical of autophagy, including the formation of autophagosomes. The TUNEL positivity and a change in morphology of mitochondria and chloroplasts indicate the passage to an apoptotic-like PCD phase, while the cellular remnants undergo a final process resembling at least partially (ER swelling) necrotic morphological syndromes, eventually leading to a mainly lipidic cell corpse still separated from the functional megaspore by a callose layer.

  18. Cell death and survival signalling in the cardiovascular system.

    PubMed

    Tucka, Joanna; Bennett, Martin; Littlewood, Trevor

    2012-01-01

    The loss of cells is an important factor in many diseases, including those of the cardiovascular system. Whereas apoptosis is an essential process in development and tissue homeostasis, its occurrence is often associated with various pathologies. Apoptosis of neurons that fail to make appropriate connections is essential for the selection of correct neural signalling in the developing embryo, but its appearance in adults is often associated with neurodegenerative disease. Similarly, in the cardiovascular system, remodeling of the mammalian outflow tract during the transition from a single to dual series circulation with four chambers is accompanied by a precise pattern of cell death, but apoptosis of cardiomyocytes contributes to ischemia-reperfusion injury in the heart. In many cases, it is unclear whether apoptosis represents a causative association or merely a consequence of the disease itself. There are many excellent reviews on cell death in the cardiovascular system (1-5); in this review we outline the critical signalling pathways that promote the survival of cardiovascular cells, and their relevance to both physiological cell death and disease.

  19. DNA methylation and differential gene regulation in photoreceptor cell death

    PubMed Central

    Farinelli, P; Perera, A; Arango-Gonzalez, B; Trifunovic, D; Wagner, M; Carell, T; Biel, M; Zrenner, E; Michalakis, S; Paquet-Durand, F; Ekström, P A R

    2014-01-01

    Retinitis pigmentosa (RP) defines a group of inherited degenerative retinal diseases causing progressive loss of photoreceptors. To this day, RP is still untreatable and rational treatment development will require a thorough understanding of the underlying cell death mechanisms. Methylation of the DNA base cytosine by DNA methyltransferases (DNMTs) is an important epigenetic factor regulating gene expression, cell differentiation, cell death, and survival. Previous studies suggested an involvement of epigenetic mechanisms in RP, and in this study, increased cytosine methylation was detected in dying photoreceptors in the rd1, rd2, P23H, and S334ter rodent models for RP. Ultrastructural analysis of photoreceptor nuclear morphology in the rd1 mouse model for RP revealed a severely altered chromatin structure during retinal degeneration that coincided with an increased expression of the DNMT isozyme DNMT3a. To identify disease-specific differentially methylated DNA regions (DMRs) on a genomic level, we immunoprecipitated methylated DNA fragments and subsequently analyzed them with a targeted microarray. Genome-wide comparison of DMRs between rd1 and wild-type retina revealed hypermethylation of genes involved in cell death and survival as well as cell morphology and nervous system development. When correlating DMRs with gene expression data, we found that hypermethylation occurred alongside transcriptional repression. Consistently, motif analysis showed that binding sites of several important transcription factors for retinal physiology were hypermethylated in the mutant model, which also correlated with transcriptional silencing of their respective target genes. Finally, inhibition of DNMTs in rd1 organotypic retinal explants using decitabine resulted in a substantial reduction of photoreceptor cell death, suggesting inhibition of DNA methylation as a potential novel treatment in RP. PMID:25476906

  20. Sensitization of acute lymphoblastic leukemia cells for LCL161-induced cell death by targeting redox homeostasis.

    PubMed

    Haß, Christina; Belz, Katharina; Schoeneberger, Hannah; Fulda, Simone

    2016-04-01

    Disturbed redox homeostasis with both elevated reactive oxygen species (ROS) levels and antioxidant defense mechanisms has been reported in acute lymphoblastic leukemia (ALL). We therefore hypothesized that inhibition of pathways responsible for ROS detoxification renders ALL cells more susceptible for cell death. Here, we report that pharmacological inhibitors of key pathways for the elimination of ROS, i.e. Erastin, buthionine sulfoximine (BSO) and Auranofin, sensitize ALL cells for cell death upon treatment with the Smac mimetic LCL161 that antagonizes Inhibitor of Apoptosis (IAP) proteins. Erastin, BSO or Auranofin significantly increase LCL161-induced cell death and also act in concert with LCL161 to profoundly suppress long-term clonogenic survival in several ALL cell lines. Erastin or BSO cooperates with LCL161 to stimulate ROS production and lipid peroxidation prior to cell death. ROS production and lipid peroxidation are required for this cotreatment-induced cell death, since ROS scavengers or pharmacological inhibition of lipid peroxidation provides significant protection against cell death. These results emphasize that inhibition of antioxidant defense mechanisms can serve as a potent approach to prime ALL cells for LCL161-induced cell death.

  1. Intracellular Delivery of Synthetic dsRNA to Leukemic Cells Induces Apoptotic and Necrotic Cell Death.

    PubMed

    Mahmud, S M; Mek, K J; Idris, A

    2016-01-01

    The type of tumour cell death dictates the type of adaptive immune response mounted against the tumours. In haematological malignancies such as acute myeloid leukaemia (AML), immune evasion due to the poor immunogenicity of leukemic cells is a major hurdle in generating an effective immune response. Transfection of synthetic dsRNA, poly I:C, into leukemic cells to trigger tumour cell death and enhance immunogenicity of the tumour is a promising immunotherapeutic approach. However, the temporal cell death kinetics of poly I:C-electroporated AML cells has not been thoroughly investigated. Electroporation of U937 cells, a human AML cell line, with a high dose of poly I:C resulted in cytotoxicity as early as 1 h post-transfection. Flow cytometric analysis revealed the temporal switch from early apoptosis to late apoptosis/secondary necrosis in poly I:C-electroporated cells in which the nuclear morphology at later time points was consistent with necrotic cell death. Our brief findings demonstrated the temporal cell death kinetics of dsRNA-transfected leukemic cells. This finding is an important development in the field of dsRNA immunotherapy for leukaemia as understanding the type of cell death elicited by transfected dsRNA will dictate the type of immune response to be directed against leukemic cells. PMID:27187041

  2. Programmed cell death and clearance of cell corpses in Caenorhabditis elegans.

    PubMed

    Wang, Xiaochen; Yang, Chonglin

    2016-06-01

    Programmed cell death is critical to the development of diverse animal species from C. elegans to humans. In C. elegans, the cell death program has three genetically distinguishable phases. During the cell suicide phase, the core cell death machinery is activated through a protein interaction cascade. This activates the caspase CED-3, which promotes numerous pro-apoptotic activities including DNA degradation and exposure of the phosphatidylserine "eat me" signal on the cell corpse surface. Specification of the cell death fate involves transcriptional activation of the cell death initiator EGL-1 or the caspase CED-3 by coordinated actions of specific transcription factors in distinct cell types. In the cell corpse clearance stage, recognition of cell corpses by phagocytes triggers several signaling pathways to induce phagocytosis of apoptotic cell corpses. Cell corpse-enclosing phagosomes ultimately fuse with lysosomes for digestion of phagosomal contents. This article summarizes our current knowledge about programmed cell death and clearance of cell corpses in C. elegans. PMID:27048817

  3. Cell death induced by the Alternaria mycotoxin Alternariol.

    PubMed

    Bensassi, Fatma; Gallerne, Cindy; Sharaf El Dein, Ossama; Hajlaoui, Mohamed Rabeh; Bacha, Hassen; Lemaire, Christophe

    2012-09-01

    Mycotoxins are unavoidable contaminants of most foods and feeds, and some are known to be detrimental to human health. It is thus worthwhile to understand how cells of the intestinal system, one of the primary targets of these toxins, respond to their toxic effects. In this study, human colon carcinoma cells were used to elucidate the cell death mode and the pathways triggered by Alternariol (AOH), the most important mycotoxin produced by Alternaria species, which are the most common mycoflora infecting small grain cereals worldwide. Treatment of cells with AOH resulted in a loss of cell viability by inducing apoptosis. AOH-induced apoptosis was mediated through a mitochondria-dependent pathway, characterized by a p53 activation, an opening of the mitochondrial permeability transition pore (PTP), a loss of mitochondrial transmembrane potential (ΔΨm), a downstream generation of O(2)(*-) and caspase 9 and 3 activation. Besides, deficiency of the pro-apoptotic protein Bax partially protected cells against AOH-induced mitochondrial alterations. In addition, experiments performed on purified mitochondria indicated that AOH does not directly target this organelle to induce cell death. Our results demonstrate for the first time that AOH-induced cytotoxicity is mediated by activation of the mitochondrial pathway of apoptosis in human colon carcinoma cells.

  4. [Selective "death programs" or pleiotropic"life programs"? Looking for programmed cell death in the light of evolution].

    PubMed

    Ameisen, Jean-Claude

    2005-01-01

    "Nothing in biology makes sense except in the light of evolution", wrote Theodosius Dobzhansky, one of the founders of the Modern Synthesis that led to the unification of evolutionary theory and genetics in the midst of the 20th century. Programmed cell death is a genetically regulated process of cell suicide that is central to the development, homeostasis and integrity of multicellular organisms. Conversely, the dysregulation of mechanisms controlling cell suicide plays a role in the pathogenesis of a wide range of diseases. While great progress has been achieved in the unveiling of the molecular mechanisms of programmed cell death, a new, and somehow puzzling level of complexity has recently begun to emerge, suggesting i) that several different self destruction pathways may exist and operate in parallel in our cells, and ii) that molecular effectors of cell suicide might also perform other functions unrelated to cell death induction and crucial to cell survival, such as cell differentiation, metabolism, and the regulation of the cell cycle. These new findings, with important physiopathological and therapeutic implications, seem at odds with the paradigm of programmed cell death derived from the studies of Caenorhabditis elegans, which led to the concept of the existence of selective, bona fide death genes that emerged and became selected for their sole capacity to execute or repress cell death. In this review, I will argue that this new level of complexity might only make sense and be understood when considered in a broader evolutionary context than that of our phylogenetic divergence from C. elegans. A new view of the regulated cell death pathways emerges when one attempts to ask the question of when and how they may have become selected during a timeline of 4 billion years, at the level of ancestral single-celled organisms, including the bacteria. I will argue that there may be no such thing as a bona fide genetic cell death program. Rather, in the framework of

  5. Glucose Levels in Culture Medium Determine Cell Death Mode in MPP+-treated Dopaminergic Neuronal Cells

    PubMed Central

    Yoon, So-Young

    2015-01-01

    We previously demonstrated that 1-methyl-4-phenylpyridinium (MPP+) causes caspase-independent, non-apoptotic death of dopaminergic (DA) neuronal cells. Here, we specifically examined whether change of glucose concentration in culture medium may play a role for determining cell death modes of DA neurons following MPP+ treatment. By incubating MN9D cells in medium containing varying concentrations of glucose (5~35 mM), we found that cells underwent a distinct cell death as determined by morphological and biochemical criteria. At 5~10 mM glucose concentration (low glucose levels), MPP+ induced typical of the apoptotic dell death accompanied with caspase activation and DNA fragmentation as well as cell shrinkage. In contrast, MN9D cells cultivated in medium containing more than 17.5 mM (high glucose levels) did not demonstrate any of these changes. Subsequently, we observed that MPP+ at low glucose levels but not high glucose levels led to ROS generation and subsequent JNK activation. Therefore, MPP+-induced cell death only at low glucose levels was significantly ameliorated following co-treatment with ROS scavenger, caspase inhibitor or JNK inhibitor. We basically confirmed the quite similar pattern of cell death in primary cultures of DA neurons. Taken together, our results suggest that a biochemically distinct cell death mode is recruited by MPP+ depending on extracellular glucose levels. PMID:26412968

  6. In vitro apoptotic cell death during erythroid differentiation.

    PubMed

    Zamai, L; Burattini, S; Luchetti, F; Canonico, B; Ferri, P; Melloni, E; Gonelli, A; Guidotti, L; Papa, S; Falcieri, E

    2004-03-01

    Erythropoiesis occurs in bone marrow and it has been shown that during in vivo erythroid differentiation some immature erythroblasts undergo apoptosis. In this regard, it is known that immature erythroblasts are FasL- and TRAIL-sensitive and can be killed by cells expressing these ligand molecules. In the present study, we have investigated the cell death phenomenon that occurs during a common unilineage model of erythroid development. Purified CD34+ human haemopoietic progenitors were cultured in vitro in the presence of SCF, IL-3 and erythropoietin. Their differentiation stages and apoptosis were followed by multiple technical approaches. Flow cytometric evaluation of surface and intracellular molecules revealed that glycophorin A appeared at day 3-4 of incubation and about 75% of viable cells co-expressed high density glycophorin A (Gly(bright)) and adult haemoglobin at day 14 of culture, indicating that this system reasonably recapitulates in vivo normal erythropoiesis. Interestingly, when mature (Gly(bright)) erythroid cells reached their higher percentages (day 14) almost half of cultured cells were apoptotic. Morphological studies indicated that the majority of dead cells contained cytoplasmic granular material typical of basophilic stage, and DNA analysis by flow cytometry and TUNEL reaction revealed nuclear fragmentation. These observations indicate that in vitro unilineage erythroid differentiation, as in vivo, is associated with apoptotic cell death of cells with characteristics of basophilic erythroblasts. We suggest that the interactions between different death receptors on immature basophilic erythroblasts with their ligands on more mature erythroblasts may contribute to induce apoptosis in vitro. PMID:15004520

  7. Bee Venom Protects against Rotenone-Induced Cell Death in NSC34 Motor Neuron Cells.

    PubMed

    Jung, So Young; Lee, Kang-Woo; Choi, Sun-Mi; Yang, Eun Jin

    2015-09-01

    Rotenone, an inhibitor of mitochondrial complex I of the mitochondrial respiratory chain, is known to elevate mitochondrial reactive oxygen species and induce apoptosis via activation of the caspase-3 pathway. Bee venom (BV) extracted from honey bees has been widely used in oriental medicine and contains melittin, apamin, adolapin, mast cell-degranulating peptide, and phospholipase A₂. In this study, we tested the effects of BV on neuronal cell death by examining rotenone-induced mitochondrial dysfunction. NSC34 motor neuron cells were pretreated with 2.5 μg/mL BV and stimulated with 10 μM rotenone to induce cell toxicity. We assessed cell death by Western blotting using specific antibodies, such as phospho-ERK1/2, phospho-JNK, and cleaved capase-3 and performed an MTT assay for evaluation of cell death and mitochondria staining. Pretreatment with 2.5 μg/mL BV had a neuroprotective effect against 10 μM rotenone-induced cell death in NSC34 motor neuron cells. Pre-treatment with BV significantly enhanced cell viability and ameliorated mitochondrial impairment in rotenone-treated cellular model. Moreover, BV treatment inhibited the activation of JNK signaling and cleaved caspase-3 related to cell death and increased ERK phosphorylation involved in cell survival in rotenone-treated NSC34 motor neuron cells. Taken together, we suggest that BV treatment can be useful for protection of neurons against oxidative stress or neurotoxin-induced cell death. PMID:26402700

  8. Bee Venom Protects against Rotenone-Induced Cell Death in NSC34 Motor Neuron Cells

    PubMed Central

    Jung, So Young; Lee, Kang-Woo; Choi, Sun-Mi; Yang, Eun Jin

    2015-01-01

    Rotenone, an inhibitor of mitochondrial complex I of the mitochondrial respiratory chain, is known to elevate mitochondrial reactive oxygen species and induce apoptosis via activation of the caspase-3 pathway. Bee venom (BV) extracted from honey bees has been widely used in oriental medicine and contains melittin, apamin, adolapin, mast cell-degranulating peptide, and phospholipase A2. In this study, we tested the effects of BV on neuronal cell death by examining rotenone-induced mitochondrial dysfunction. NSC34 motor neuron cells were pretreated with 2.5 μg/mL BV and stimulated with 10 μM rotenone to induce cell toxicity. We assessed cell death by Western blotting using specific antibodies, such as phospho-ERK1/2, phospho-JNK, and cleaved capase-3 and performed an MTT assay for evaluation of cell death and mitochondria staining. Pretreatment with 2.5 μg/mL BV had a neuroprotective effect against 10 μM rotenone-induced cell death in NSC34 motor neuron cells. Pre-treatment with BV significantly enhanced cell viability and ameliorated mitochondrial impairment in rotenone-treated cellular model. Moreover, BV treatment inhibited the activation of JNK signaling and cleaved caspase-3 related to cell death and increased ERK phosphorylation involved in cell survival in rotenone-treated NSC34 motor neuron cells. Taken together, we suggest that BV treatment can be useful for protection of neurons against oxidative stress or neurotoxin-induced cell death. PMID:26402700

  9. Vanadium pentoxide induces activation and death of endothelial cells.

    PubMed

    Montiel-Dávalos, Angélica; Gonzalez-Villava, Adriana; Rodriguez-Lara, Vianey; Montaño, Luis Felipe; Fortoul, Teresa I; López-Marure, Rebeca

    2012-01-01

    Vanadium is a transition metal released into the atmosphere, as air-suspended particles, as a result of the combustion of fossil fuels and some metallurgic industry activities. Air-suspended particle pollution causes inflammation-related processes such as thrombosis and other cardiovascular events. Our aim was to evaluate the effect of vanadium pentoxide (V2O5) on endothelial cells since they are key participants in the pathogenesis of several cardiovascular and inflammatory diseases. Cell adhesion, the expression of adhesion molecules and oxidative stress, as well as proliferation, morphology and cell death of human umbilical vein endothelial cells (HUVECs) exposed to V2O5, were evaluated. Vanadium pentoxide at a 3.12 µg cm(-2) concentration induced an enhanced adhesion of the U937 macrophage cell line to HUVECs, owing to an increased expression of late adhesion molecules. HUVECs exposed to V2O5 showed an increase in ROS and nitric oxide production, and a diminished proliferation. These changes in vanadium-treated HUVECs were accompanied by severe morphological changes and apoptotic cell death. Vanadium pentoxide induced serious endothelial cell damage, probably related to the increased cardiovascular morbidity and mortality observed in individuals living in highly air-polluted areas. PMID:21721017

  10. Alcohol-induced cell death in the embryo.

    PubMed

    Smith, S M

    1997-01-01

    Exposure to alcohol during gestation can have profound consequences, but not all cells within the embryo are affected equally. Recent advances in molecular embryology have allowed an exploration of this variation. Much of this research has focused on the embryo's vulnerability to the facial malformations characteristic of fetal alcohol syndrome. Studies using mice and chicks show that alcohol exposure at specific stages of early embryo development results in significant death among the cells destined to give rise to facial structures (i.e., cranial neural crest cells). This type of cell death is through activation of the cell's own "self-destruct" machinery (i.e., apoptosis). Researchers have advanced several theories to explain how alcohol triggers apoptosis in the neural crest cells. These theories include deficiency in a type of vitamin A compound, retinoic acid; reduced levels of antioxidant compounds (i.e., free radical scavengers) that protect against damage from toxic oxygen molecules (i.e., free radicals); and interference with the cell's normal internal communication pathways. PMID:15706739

  11. Molecular mechanisms of cell death in intervertebral disc degeneration (Review)

    PubMed Central

    ZHANG, FAN; ZHAO, XUELING; SHEN, HONGXING; ZHANG, CAIGUO

    2016-01-01

    Intervertebral discs (IVDs) are complex structures that consist of three parts, namely, nucleus pulposus, annulus fibrosus and cartilage endplates. With aging, IVDs gradually degenerate as a consequence of many factors, such as microenvironment changes and cell death. Human clinical trial and animal model studies have documented that cell death, particularly apoptosis and autophagy, significantly contribute to IVD degeneration. The mechanisms underlying this phenomenon include the activation of apoptotic pathways and the regulation of autophagy in response to nutrient deprivation and multiple stresses. In this review, we briefly summarize recent progress in understanding the function and regulation of apoptosis and autophagy signaling pathways. In particular, we focus on studies that reveal the functional mechanisms of these pathways in IVD degeneration. PMID:27121482

  12. Physical modalities inducing immunogenic tumor cell death for cancer immunotherapy

    PubMed Central

    Adkins, Irena; Fucikova, Jitka; Garg, Abhishek D; Agostinis, Patrizia; Špíšek, Radek

    2015-01-01

    The concept of immunogenic cancer cell death (ICD), as originally observed during the treatment with several chemotherapeutics or ionizing irradiation, has revolutionized the view on the development of new anticancer therapies. ICD is defined by endoplasmic reticulum (ER) stress response, reactive oxygen species (ROS) generation, emission of danger-associated molecular patterns and induction of antitumor immunity. Here we describe known and emerging cancer cell death-inducing physical modalities, such as ionizing irradiation, ultraviolet C light, Photodynamic Therapy (PDT) with Hypericin, high hydrostatic pressure (HHP) and hyperthermia (HT), which have been shown to elicit effective antitumor immunity. We discuss the evidence of ICD induced by these modalities in cancer patients together with their applicability in immunotherapeutic protocols and anticancer vaccine development. PMID:25964865

  13. Cytofluorometric Quantification of Cell Death Elicited by NLR Proteins.

    PubMed

    Sica, Valentina; Manic, Gwenola; Kroemer, Guido; Vitale, Ilio; Galluzzi, Lorenzo

    2016-01-01

    Nucleotide-binding domain and leucine-rich repeat containing (NLR) proteins, also known as NOD-like receptors, are critical components of the molecular machinery that senses intracellular danger signals to initiate an innate immune response against invading pathogens or endogenous sources of hazard. The best characterized effect of NLR signaling is the secretion of various cytokines with immunostimulatory effects, including interleukin (IL)-1β and IL-18. Moreover, at least under specific circumstances, NLRs can promote regulated variants of cell death. Here, we detail two protocols for the cytofluorometric quantification of cell death-associated parameters that can be conveniently employed to assess the lethal activity of specific NLRs or their ligands.

  14. Mitochondria, calcium and cell death: A deadly triad in neurodegeneration

    PubMed Central

    Celsi, Fulvio; Pizzo, Paola; Brini, Marisa; Leo, Sara; Fotino, Carmen; Pinton, Paolo; Rizzuto, Rosario

    2009-01-01

    Mitochondrial Ca2+ accumulation is a tightly controlled process, in turn regulating functions as diverse as aerobic metabolism and induction of cell death. The link between Ca2+ (dys)regulation, mitochondria and cellular derangement is particularly evident in neurodegenerative disorders, in which genetic models and environmental factors allowed to identify common traits in the pathogenic routes. We will here summarize: i) the current view of mechanisms and functions of mitochondrial Ca2+ homeostasis, ii) the basic principles of organelle Ca2+ transport, iii) the role of Ca2+ in neuronal cell death, and iv) the new information on the pathogenesis of Alzheimer's, Huntington's and Parkinson's diseases, highlighting the role of Ca2+ and mitochondria. PMID:19268425

  15. Identification of a mitotic death signature in cancer cell lines.

    PubMed

    Sakurikar, Nandini; Eichhorn, Joshua M; Alford, Sarah E; Chambers, Timothy C

    2014-02-28

    This study examined the molecular mechanism of action of anti-mitotic drugs. The hypothesis was tested that death in mitosis occurs through sustained mitotic arrest with robust Cdk1 signaling causing complete phosphorylation of Mcl-1 and Bcl-xL, and conversely, that mitotic slippage is associated with incomplete phosphorylation of Mcl-1/Bcl-xL. The results, obtained from studying six different cancer cell lines, strongly support the hypothesis and identify for the first time a unique molecular signature for mitotic death. The findings represent an important advance in understanding anti-mitotic drug action and provide insight into cancer cell susceptibility to such drugs which has important clinical implications. PMID:24099917

  16. Identification of a mitotic death signature in cancer cell lines.

    PubMed

    Sakurikar, Nandini; Eichhorn, Joshua M; Alford, Sarah E; Chambers, Timothy C

    2014-02-28

    This study examined the molecular mechanism of action of anti-mitotic drugs. The hypothesis was tested that death in mitosis occurs through sustained mitotic arrest with robust Cdk1 signaling causing complete phosphorylation of Mcl-1 and Bcl-xL, and conversely, that mitotic slippage is associated with incomplete phosphorylation of Mcl-1/Bcl-xL. The results, obtained from studying six different cancer cell lines, strongly support the hypothesis and identify for the first time a unique molecular signature for mitotic death. The findings represent an important advance in understanding anti-mitotic drug action and provide insight into cancer cell susceptibility to such drugs which has important clinical implications.

  17. Programmed cell death in plants: lessons from bacteria?

    PubMed Central

    Wang, Junhui; Bayles, Kenneth W.

    2012-01-01

    Programmed cell death (PCD) has well-established roles in the development and physiology of animals, plants, and fungi. Although aspects of PCD control appear evolutionarily conserved between these organisms, the extent of conservation remains controversial. Recently, a putative bacterial PCD protein homolog in plants was found to play a significant role in cell death control, indicating a conservation of function between these highly divergent organisms. Interestingly, these bacterial proteins are thought to be evolutionarily linked to the Bcl-2 family of proteins. In this Opinion article, we propose a new unifying model to describe the relationship between bacterial and plant PCD systems and propose that the underlying control of PCD is conserved across at least three Kingdoms of life. PMID:23083702

  18. Ayanin diacetate-induced cell death is amplified by TRAIL in human leukemia cells

    SciTech Connect

    Marrero, Maria Teresa; Estevez, Sara; Negrin, Gledy; Quintana, Jose; Leon, Francisco; Estevez, Francisco

    2012-11-09

    Highlights: Black-Right-Pointing-Pointer Ayanin diacetate as apoptotic inducer in leukemia cells. Black-Right-Pointing-Pointer Cell death was prevented by caspase inhibitors and by the overexpression of Bcl-x{sub L}. Black-Right-Pointing-Pointer The intrinsic and the extrinsic pathways are involved in the mechanism of action. Black-Right-Pointing-Pointer Death receptors are up-regulated and TRAIL enhances apoptotic cell death. -- Abstract: Here we demonstrate that the semi-synthetic flavonoid ayanin diacetate induces cell death selectively in leukemia cells without affecting the proliferation of normal lymphocytes. Incubation of human leukemia cells with ayanin diacetate induced G{sub 2}-M phase cell cycle arrest and apoptosis which was prevented by the non-specific caspase inhibitor z-VAD-fmk and reduced by the overexpression of Bcl-x{sub L}. Ayanin diacetate-induced cell death was found to be associated with: (i) loss of inner mitochondrial membrane potential, (ii) the release of cytochrome c, (iii) the activation of multiple caspases, (iv) cleavage of poly(ADP-ribose) polymerase and (v) the up-regulation of death receptors for TRAIL, DR4 and DR5. Moreover, the combined treatment with ayanin diacetate and TRAIL amplified cell death, compared to single treatments. These results provide a basis for further exploring the potential applications of this combination for the treatment of cancer.

  19. Orexin A attenuates palmitic acid-induced hypothalamic cell death.

    PubMed

    Duffy, Cayla M; Nixon, Joshua P; Butterick, Tammy A

    2016-09-01

    Palmitic acid (PA), an abundant dietary saturated fatty acid, contributes to obesity and hypothalamic dysregulation in part through increase in oxidative stress, insulin resistance, and neuroinflammation. Increased production of reactive oxygen species (ROS) as a result of PA exposure contributes to the onset of neuronal apoptosis. Additionally, high fat diets lead to changes in hypothalamic gene expression profiles including suppression of the anti-apoptotic protein B cell lymphoma 2 (Bcl-2) and upregulation of the pro-apoptotic protein B cell lymphoma 2 associated X protein (Bax). Orexin A (OXA), a hypothalamic peptide important in obesity resistance, also contributes to neuroprotection. Prior studies have demonstrated that OXA attenuates oxidative stress induced cell death. We hypothesized that OXA would be neuroprotective against PA induced cell death. To test this, we treated an immortalized hypothalamic cell line (designated mHypoA-1/2) with OXA and PA. We demonstrate that OXA attenuates PA-induced hypothalamic cell death via reduced caspase-3/7 apoptosis, stabilization of Bcl-2 gene expression, and reduced Bax/Bcl-2 gene expression ratio. We also found that OXA inhibits ROS production after PA exposure. Finally, we show that PA exposure in mHypoA-1/2 cells significantly reduces basal respiration, maximum respiration, ATP production, and reserve capacity. However, OXA treatment reverses PA-induced changes in intracellular metabolism, increasing basal respiration, maximum respiration, ATP production, and reserve capacity. Collectively, these results support that OXA protects against PA-induced hypothalamic dysregulation, and may represent one mechanism through which OXA can ameliorate effects of obesogenic diet on brain health. PMID:27449757

  20. Detection of programmed cell death using fluorescence energy transfer.

    PubMed Central

    Xu, X; Gerard, A L; Huang, B C; Anderson, D C; Payan, D G; Luo, Y

    1998-01-01

    Fluorescence energy transfer (FRET) can be generated when green fluorescent protein (GFP) and blue fluorescent protein (BFP) are covalently linked together by a short peptide. Cleavage of this linkage by protease completely eliminates FRET effect. Caspase-3 (CPP32) is an important cellular protease activated during programmed cell death. An 18 amino acid peptide containing CPP32 recognition sequence, DEVD, was used to link GFP and BFP together. CPP32 activation can be monitored by FRET assay during the apoptosis process. PMID:9518501

  1. Calcium oxalate toxicity in renal epithelial cells: the mediation of crystal size on cell death mode.

    PubMed

    Sun, X-Y; Gan, Q-Z; Ouyang, J-M

    2015-01-01

    The cytotoxicity of calcium oxalate (CaOx) in renal epithelial cells has been studied extensively, but the cell death mode induced by CaOx with different physical properties, such as crystal size and crystal phase, has not been studied in detail. In this study, we comparatively investigated the differences of cell death mode induced by nano-sized (50 nm) and micron-sized (10 μm) calcium oxalate monohydrate (COM) and calcium oxalate dihydrate (COD) to explore the cell death mechanism. The effect of the exposure of nano-/micron-sized COM and COD crystals toward the African green monkey renal epithelial (Vero) cells were investigated by detecting cell cytoskeleton changes, lysosomal integrity, mitochondrial membrane potential (Δψm), apoptosis and/or necrosis, osteopontin (OPN) expression, and malondialdehyde (MDA) release. Nano-/micron-sized COM and COD crystals could cause apoptosis and necrosis simultaneously. Nano-sized crystals primarily caused apoptotic cell death, leading to cell shrinkage, phosphatidylserine ectropion, and nuclear shrinkage, whereas micron-sized crystals primarily caused necrotic cell death, leading to cell swelling and cell membrane and lysosome rupture. Nano-sized COM and COD crystals induced much greater cell death (sum of apoptosis and necrosis) than micron-sized crystals, and COM crystals showed higher cytotoxicity than the same-sized COD crystals. Both apoptosis and necrosis could lead to mitochondria depolarization and elevate the expression of OPN and the generation of lipid peroxidation product MDA. The amount of expressed OPN and generated MDA was positively related to cell injury degree. The physicochemical properties of crystals could affect the cell death mode. The results of this study may provide a basis for future studies on cell death mechanisms.

  2. Calcium oxalate toxicity in renal epithelial cells: the mediation of crystal size on cell death mode

    PubMed Central

    Sun, X-Y; Gan, Q-Z; Ouyang, J-M

    2015-01-01

    The cytotoxicity of calcium oxalate (CaOx) in renal epithelial cells has been studied extensively, but the cell death mode induced by CaOx with different physical properties, such as crystal size and crystal phase, has not been studied in detail. In this study, we comparatively investigated the differences of cell death mode induced by nano-sized (50 nm) and micron-sized (10 μm) calcium oxalate monohydrate (COM) and calcium oxalate dihydrate (COD) to explore the cell death mechanism. The effect of the exposure of nano-/micron-sized COM and COD crystals toward the African green monkey renal epithelial (Vero) cells were investigated by detecting cell cytoskeleton changes, lysosomal integrity, mitochondrial membrane potential (Δψm), apoptosis and/or necrosis, osteopontin (OPN) expression, and malondialdehyde (MDA) release. Nano-/micron-sized COM and COD crystals could cause apoptosis and necrosis simultaneously. Nano-sized crystals primarily caused apoptotic cell death, leading to cell shrinkage, phosphatidylserine ectropion, and nuclear shrinkage, whereas micron-sized crystals primarily caused necrotic cell death, leading to cell swelling and cell membrane and lysosome rupture. Nano-sized COM and COD crystals induced much greater cell death (sum of apoptosis and necrosis) than micron-sized crystals, and COM crystals showed higher cytotoxicity than the same-sized COD crystals. Both apoptosis and necrosis could lead to mitochondria depolarization and elevate the expression of OPN and the generation of lipid peroxidation product MDA. The amount of expressed OPN and generated MDA was positively related to cell injury degree. The physicochemical properties of crystals could affect the cell death mode. The results of this study may provide a basis for future studies on cell death mechanisms. PMID:27551481

  3. p21(WAF1) (/Cip1) limits senescence and acinar-to-ductal metaplasia formation during pancreatitis.

    PubMed

    Grabliauskaite, Kamile; Hehl, Adrian B; Seleznik, Gitta M; Saponara, Enrica; Schlesinger, Kathryn; Zuellig, Richard A; Dittmann, Anja; Bain, Martha; Reding, Theresia; Sonda, Sabrina; Graf, Rolf

    2015-02-01

    Trans-differentiation of pancreatic acinar cells into ductal-like lesions, a process defined as acinar-to-ductal metaplasia (ADM), is observed in the course of organ regeneration following pancreatitis. In addition, ADM is found in association with pre-malignant PanIN lesions and correlates with an increased risk of pancreatic adenocarcinoma (PDAC). Human PDAC samples show down-regulation of p21(WAF1) (/Cip1) , a key regulator of cell cycle and cell differentiation. Here we investigated whether p21 down-regulation is implicated in controlling the early events of acinar cell trans-differentiation and ADM formation. p21-mediated regulation of ADM formation and regression was analysed in vivo during the course of cerulein-induced pancreatitis, using wild-type (WT) and p21-deficient (p21(-/-) ) mice. Biochemical and immunohistochemical methods were used to evaluate disease progression over 2 weeks of the disease and during a recovery phase. We found that p21 was strongly up-regulated in WT acinar cells during pancreatitis, while it was absent in ADM areas, suggesting that p21 down-regulation is associated with ADM formation. In support of this hypothesis, p21(-/-) mice showed a significant increase in number and size of metaplasia. In addition, p21 over-expression in acinar cells reduced ADM formation in vitro, suggesting that the protein regulates the metaplastic transition in a cell-autonomous manner. p21(-/-) mice displayed increased expression and relocalization of β-catenin both during pancreatitis and in the subsequent recovery phase. Finally, loss of p21 was accompanied by increased DNA damage and development of senescence. Our findings are consistent with a gate-keeper role of p21 in acinar cells to limit senescence activation and ADM formation during pancreatic regeneration. PMID:25212177

  4. p21(WAF1) (/Cip1) limits senescence and acinar-to-ductal metaplasia formation during pancreatitis.

    PubMed

    Grabliauskaite, Kamile; Hehl, Adrian B; Seleznik, Gitta M; Saponara, Enrica; Schlesinger, Kathryn; Zuellig, Richard A; Dittmann, Anja; Bain, Martha; Reding, Theresia; Sonda, Sabrina; Graf, Rolf

    2015-02-01

    Trans-differentiation of pancreatic acinar cells into ductal-like lesions, a process defined as acinar-to-ductal metaplasia (ADM), is observed in the course of organ regeneration following pancreatitis. In addition, ADM is found in association with pre-malignant PanIN lesions and correlates with an increased risk of pancreatic adenocarcinoma (PDAC). Human PDAC samples show down-regulation of p21(WAF1) (/Cip1) , a key regulator of cell cycle and cell differentiation. Here we investigated whether p21 down-regulation is implicated in controlling the early events of acinar cell trans-differentiation and ADM formation. p21-mediated regulation of ADM formation and regression was analysed in vivo during the course of cerulein-induced pancreatitis, using wild-type (WT) and p21-deficient (p21(-/-) ) mice. Biochemical and immunohistochemical methods were used to evaluate disease progression over 2 weeks of the disease and during a recovery phase. We found that p21 was strongly up-regulated in WT acinar cells during pancreatitis, while it was absent in ADM areas, suggesting that p21 down-regulation is associated with ADM formation. In support of this hypothesis, p21(-/-) mice showed a significant increase in number and size of metaplasia. In addition, p21 over-expression in acinar cells reduced ADM formation in vitro, suggesting that the protein regulates the metaplastic transition in a cell-autonomous manner. p21(-/-) mice displayed increased expression and relocalization of β-catenin both during pancreatitis and in the subsequent recovery phase. Finally, loss of p21 was accompanied by increased DNA damage and development of senescence. Our findings are consistent with a gate-keeper role of p21 in acinar cells to limit senescence activation and ADM formation during pancreatic regeneration.

  5. Cell birth, cell death, cell diversity and DNA breaks: how do they all fit together?

    NASA Technical Reports Server (NTRS)

    Gilmore, E. C.; Nowakowski, R. S.; Caviness, V. S. Jr; Herrup, K.

    2000-01-01

    Substantial death of migrating and differentiating neurons occurs within the developing CNS of mice that are deficient in genes required for repair of double-stranded DNA breaks. These findings suggest that large-scale, yet previously unrecognized, double-stranded DNA breaks occur normally in early postmitotic and differentiating neurons. Moreover, they imply that cell death occurs if the breaks are not repaired. The cause and natural function of such breaks remains a mystery; however, their occurrence has significant implications. They might be detected by histological methods that are sensitive to DNA fragmentation and mistakenly interpreted to indicate cell death when no relationship exists. In a broader context, there is now renewed speculation that DNA recombination might be occurring during neuronal development, similar to DNA recombination in developing lymphocytes. If this is true, the target gene(s) of recombination and their significance remain to be determined.

  6. Programmed Cell Death in Animal Development and Disease

    PubMed Central

    Fuchs, Yaron; Steller, Hermann

    2015-01-01

    Programmed Cell Death (PCD) plays a fundamental role in animal development and tissue homeostasis. Abnormal regulation of this process is associated with a wide variety of human diseases, including immunological and developmental disorders, neuro-degeneration, and cancer. Here, we provide a brief historical overview of the field and reflect on myriad functions carried out by PCD during development and explore how PCD is regulated. We also focus on the function and regulation of apoptotic proteins, including caspases, the key executioners of apoptosis, highlighting the non-lethal functions of these proteins in diverse developmental processes including cell differentiation and tissue remodeling. Finally, we explore a growing body of work about the connections between apoptosis, stem cells and cancer, focusing on how apoptotic cells release a variety of signals to communicate with their cellular environment, including factors that promote cell division, tissue regeneration, and wound healing. PMID:22078876

  7. Thymoquinone causes multiple effects, including cell death, on dividing plant cells.

    PubMed

    Hassanien, Sameh E; Ramadan, Ahmed M; Azeiz, Ahmed Z Abdel; Mohammed, Rasha A; Hassan, Sabah M; Shokry, Ahmed M; Atef, Ahmed; Kamal, Khalid B H; Rabah, Samar; Sabir, Jamal S M; Abuzinadah, Osama A; El-Domyati, Fotouh M; Martin, Gregory B; Bahieldin, Ahmed

    2013-01-01

    Thymoquinone (TQ) is a major constituent of Nigella sativa oil with reported anti-oxidative activity and anti-inflammatory activity in animal cells. It also inhibits proliferation and induces programmed cell death (apoptosis) in human skin cancer cells. The present study sought to detect the influence of TQ on dividing cells of three plant systems and on expression of Bcl2-associated athanogene-like (BAG-like) genes that might be involved during the process of cell death. BAG genes are known for the regulation of diverse physiological processes in animals, including apoptosis, tumorigenesis, stress responses, and cell division. Synthetic TQ at 0.1mg/mL greatly reduced wheat seed germination rate, whereas 0.2mg/mL completely inhibited germination. An Evans blue assay revealed moderate cell death in the meristematic zone of Glycine max roots after 1h of TQ treatment (0.2mg/mL), with severe cell death occurring in this zone after 2h of treatment. Light microscopy of TQ-treated (0.2mg/mL) onion hairy root tips for 1h revealed anti-mitotic activity and also cell death-associated changes, including nuclear membrane disruption and nuclear fragmentation. Transmission electron microscopy of TQ-treated cells (0.2mg/mL) for 1h revealed shrinkage of the plasma membrane, leakage of cell lysate, degradation of cell walls, enlargement of vacuoles and condensation of nuclei. Expression of one BAG-like gene, previously associated with cell death, was induced 20 min after TQ treatment in Glycine max root tip cells. Thus, TQ has multiple effects, including cell death, on dividing plant cells and plants may serve as a useful system to further investigate the mechanisms underlying the response of eukaryotic cells to TQ.

  8. Cell Cycle-Dependent Mechanisms Underlie Vincristine-Induced Death of Primary Acute Lymphoblastic Leukemia Cells.

    PubMed

    Kothari, Anisha; Hittelman, Walter N; Chambers, Timothy C

    2016-06-15

    Microtubule-targeting agents (MTA), such as the taxanes and vinca alkaloids, are used to treat a variety of cancers due to their ability to perturb microtubule dynamics. In cell culture, MTAs exert their anticancer effects primarily by causing mitotic arrest and cell death. However, accumulating indirect evidence suggests that MTAs may exert their cytotoxicity in human tumors by interfering with interphase microtubules. In this study, we sought to develop and characterize an experimental system in which to test the hypothesis that MTAs induce cell death during interphase. Primary adult acute lymphoblastic leukemia (ALL) cells treated with vincristine only weakly exhibited colocalization between mitotic and apoptotic markers and major characteristics of mitotic death, such as an increase in cells with 4N DNA content before the appearance of cells with <2N DNA content, suggesting a mixed response. Therefore, we separated ALL cells into distinct phases of the cell cycle by centrifugal elutriation, labeled cells with 5-ethynyl-2'-deoxyuridine (EdU), and then treated each population with vincristine. Cells isolated during G1 underwent cell death without evidence of EdU uptake, indicating that the cytotoxic effects of vincristine took place during G1 Conversely, cells isolated during S or G2-M phases underwent death following mitotic arrest. Thus, vincristine induces distinct death programs in primary ALL cells depending on cell-cycle phase, and cells in G1 are particularly susceptible to perturbation of interphase microtubules. Primary ALL cells may therefore provide a powerful model system in which to study the multimodal mechanisms underlying MTA-induced cell death. Cancer Res; 76(12); 3553-61. ©2016 AACR. PMID:27197148

  9. Cell Cycle-Dependent Mechanisms Underlie Vincristine-Induced Death of Primary Acute Lymphoblastic Leukemia Cells.

    PubMed

    Kothari, Anisha; Hittelman, Walter N; Chambers, Timothy C

    2016-06-15

    Microtubule-targeting agents (MTA), such as the taxanes and vinca alkaloids, are used to treat a variety of cancers due to their ability to perturb microtubule dynamics. In cell culture, MTAs exert their anticancer effects primarily by causing mitotic arrest and cell death. However, accumulating indirect evidence suggests that MTAs may exert their cytotoxicity in human tumors by interfering with interphase microtubules. In this study, we sought to develop and characterize an experimental system in which to test the hypothesis that MTAs induce cell death during interphase. Primary adult acute lymphoblastic leukemia (ALL) cells treated with vincristine only weakly exhibited colocalization between mitotic and apoptotic markers and major characteristics of mitotic death, such as an increase in cells with 4N DNA content before the appearance of cells with <2N DNA content, suggesting a mixed response. Therefore, we separated ALL cells into distinct phases of the cell cycle by centrifugal elutriation, labeled cells with 5-ethynyl-2'-deoxyuridine (EdU), and then treated each population with vincristine. Cells isolated during G1 underwent cell death without evidence of EdU uptake, indicating that the cytotoxic effects of vincristine took place during G1 Conversely, cells isolated during S or G2-M phases underwent death following mitotic arrest. Thus, vincristine induces distinct death programs in primary ALL cells depending on cell-cycle phase, and cells in G1 are particularly susceptible to perturbation of interphase microtubules. Primary ALL cells may therefore provide a powerful model system in which to study the multimodal mechanisms underlying MTA-induced cell death. Cancer Res; 76(12); 3553-61. ©2016 AACR.

  10. The variability of autophagy and cell death susceptibility

    PubMed Central

    Loos, Ben; Engelbrecht, Anna-Mart; Lockshin, Richard A.; Klionsky, Daniel J; Zakeri, Zahra

    2013-01-01

    Impaired autophagic machinery is implicated in a number of diseases such as heart disease, neurodegeneration and cancer. A common denominator in these pathologies is a dysregulation of autophagy that has been linked to a change in susceptibility to cell death. Although we have progressed in understanding the molecular machinery and regulation of the autophagic pathway, many unanswered questions remain. How does the metabolic contribution of autophagy connect with the cell’s history and how does its current autophagic flux affect metabolic status and susceptibility to undergo cell death? How does autophagic flux operate to switch metabolic direction and what are the underlying mechanisms in metabolite and energetic sensing, metabolite substrate provision and metabolic integration during the cellular stress response? In this article we focus on unresolved questions that address issues around the role of autophagy in sensing the energetic environment and its role in actively generating metabolite substrates. We attempt to provide answers by explaining how and when a change in autophagic pathway activity such as primary stress response is able to affect cell viability and when not. By addressing the dynamic metabolic relationship between autophagy, apoptosis and necrosis we provide a new perspective on the parameters that connect autophagic activity, severity of injury and cellular history in a logical manner. Last, by evaluating the cell’s condition and autophagic activity in a clear context of regulatory parameters in the intra- and extracellular environment, this review provides new concepts that set autophagy into an energetic feedback loop, that may assist in our understanding of autophagy in maintaining healthy cells or when it controls the threshold between cell death and cell survival. PMID:23846383

  11. Low zinc environment induces stress signaling, senescence and mixed cell death modalities in colon cancer cells.

    PubMed

    Rudolf, Emil; Rudolf, Kamil

    2015-12-01

    Currently it is not clear what type of the final cellular response (i.e. cell death modality or senescence) is induced upon chronic intracellular zinc depletion in colon cancer cells. To address this question, isogenic colon cancer lines SW480 and SW620 exposed to low zinc environment were studied over the period of 6 weeks. Low zinc environment reduced total as well as free intracellular zinc content in both cell lines. Decreased intracellular zinc content resulted in changes in cellular proliferation, cell cycle distribution and activation of stress signaling. In addition, colonocytes with low zinc content displayed increased levels of oxidative stress, changes in mitochondrial activity but in the absence of significant DNA damage. Towards the end of treatment (4th-6th week), exposed cells started to change morphologically, and typical markers of senescence as well as cell death appeared. Of two examined colon cancer cell lines, SW480 cells proved to activate predominantly senescent phenotype, with frequent form of demise being necrosis and mixed cell death modality but not apoptosis. Conversely, SW620 cells activated mostly cell death, with relatively equal distribution of apoptosis and mixed types, while senescent phenotypes and necrosis were present only in a small fraction of cell populations. Addition of zinc at the beginning of 4th week of treatment significantly suppressed cell death phenotypes in both cell lines but had no significant effect on senescence. In conclusion, presented results demonstrate variability of responses to chronic zinc depletion in colon cancer as modeled in vitro.

  12. Involvement of ethylene and lipid signalling in cadmium-induced programmed cell death in tomato suspension cells.

    PubMed

    Yakimova, E T; Kapchina-Toteva, V M; Laarhoven, L-J; Harren, F M; Woltering, E J

    2006-10-01

    Cadmium-induced cell death was studied in suspension-cultured tomato (Lycopersicon esculentum Mill.) cells (line MsK8) treated with CdSO(4). Within 24 h, cadmium treatment induced cell death in a concentration-dependent manner. Cell cultures showed recovery after 2-3 days which indicates the existence of an adaptation mechanism. Cadmium-induced cell death was alleviated by the addition of sub muM concentrations of peptide inhibitors specific to human caspases indicating that cell death proceeds through a mechanism with similarities to animal programmed cell death (PCD, apoptosis). Cadmium-induced cell death was accompanied by an increased production of hydrogen peroxide (H(2)O(2)) and simultaneous addition of antioxidants greatly reduced cell death. Inhibitors of phospholipase C (PLC) and phospholipase D (PLD) signalling pathway intermediates reduced cadmium-induced cell death. Treatment with the G-protein activator mastoparan and a cell permeable analogue of the lipid signal second messenger phosphatidic acid (PA) induced cell death. Ethylene, while not inducing cell death when applied alone, stimulated cadmium-induced cell death. Application of the ethylene biosynthesis inhibitor aminoethoxy vinylglycine (AVG) reduced cadmium-induced cell death, and this effect was alleviated by simultaneous treatment with ethylene. Together the results show that cadmium induces PCD exhibiting apoptotic-like features. The cell death process requires increased H(2)O(2) production and activation of PLC, PLD and ethylene signalling pathways.

  13. EFFECTS OF ETHANOL AND HYDROGEN PEROXIDE ON MOUSE LIMB BUD MESENCHYME DIFFERENTIATION AND CELL DEATH

    EPA Science Inventory

    Many of the morphological defects associated with embryonic alcohol exposure are a result of cell death. During limb development, ethanol administration produces cell death in the limb and digital defects, including postaxial ectrodactyly. Because an accumulation of reactive oxyg...

  14. Cell death stages in single apoptotic and necrotic cells monitored by Raman microspectroscopy

    PubMed Central

    Brauchle, Eva; Thude, Sibylle; Brucker, Sara Y.; Schenke-Layland, Katja

    2014-01-01

    Although apoptosis and necrosis have distinct features, the identification and discrimination of apoptotic and necrotic cell death in vitro is challenging. Immunocytological and biochemical assays represent the current gold standard for monitoring cell death pathways; however, these standard assays are invasive, render large numbers of cells and impede continuous monitoring experiments. In this study, both room temperature (RT)-induced apoptosis and heat-triggered necrosis were analyzed in individual Saos-2 and SW-1353 cells by utilizing Raman microspectroscopy. A targeted analysis of defined cell death modalities, including early and late apoptosis as well as necrosis, was facilitated based on the combination of Raman spectroscopy with fluorescence microscopy. Spectral shifts were identified in the two cell lines that reflect biochemical changes specific for either RT-induced apoptosis or heat-mediated necrosis. A supervised classification model specified apoptotic and necrotic cell death based on single cell Raman spectra. To conclude, Raman spectroscopy allows a non-invasive, continuous monitoring of cell death, which may help shedding new light on complex pathophysiological or drug-induced cell death processes. PMID:24732136

  15. Molecular mechanisms of Ebola virus pathogenesis: focus on cell death

    PubMed Central

    Falasca, L; Agrati, C; Petrosillo, N; Di Caro, A; Capobianchi, M R; Ippolito, G; Piacentini, M

    2015-01-01

    Ebola virus (EBOV) belongs to the Filoviridae family and is responsible for a severe disease characterized by the sudden onset of fever and malaise accompanied by other non-specific signs and symptoms; in 30–50% of cases hemorrhagic symptoms are present. Multiorgan dysfunction occurs in severe forms with a mortality up to 90%. The EBOV first attacks macrophages and dendritic immune cells. The innate immune reaction is characterized by a cytokine storm, with secretion of numerous pro-inflammatory cytokines, which induces a huge number of contradictory signals and hurts the immune cells, as well as other tissues. Other highly pathogenic viruses also trigger cytokine storms, but Filoviruses are thought to be particularly lethal because they affect a wide array of tissues. In addition to the immune system, EBOV attacks the spleen and kidneys, where it kills cells that help the body to regulate its fluid and chemical balance and that make proteins that help the blood to clot. In addition, EBOV causes liver, lungs and kidneys to shut down their functions and the blood vessels to leak fluid into surrounding tissues. In this review, we analyze the molecular mechanisms at the basis of Ebola pathogenesis with a particular focus on the cell death pathways induced by the virus. We also discuss how the treatment of the infection can benefit from the recent experience of blocking/modulating cell death in human degenerative diseases. PMID:26024394

  16. Programmed Cell Death Initiation and Execution in Budding Yeast

    PubMed Central

    Strich, Randy

    2015-01-01

    Apoptosis or programmed cell death (PCD) was initially described in metazoans as a genetically controlled process leading to intracellular breakdown and engulfment by a neighboring cell . This process was distinguished from other forms of cell death like necrosis by maintenance of plasma membrane integrity prior to engulfment and the well-defined genetic system controlling this process. Apoptosis was originally described as a mechanism to reshape tissues during development. Given this context, the assumption was made that this process would not be found in simpler eukaryotes such as budding yeast. Although basic components of the apoptotic pathway were identified in yeast, initial observations suggested that it was devoid of prosurvival and prodeath regulatory proteins identified in mammalian cells. However, as apoptosis became extensively linked to the elimination of damaged cells, key PCD regulatory proteins were identified in yeast that play similar roles in mammals. This review highlights recent discoveries that have permitted information regarding PCD regulation in yeast to now inform experiments in animals. PMID:26272996

  17. Role of mitochondrial function in cell death and body metabolism.

    PubMed

    Lee, Myung-Shik

    2016-01-01

    Mitochondria are the key players in apoptosis and necrosis. Mitochondrial DNA (mtDNA)-depleted r0 cells were resistant to diverse apoptosis inducers such as TNF-alpha, TNFSF10, staurosporine and p53. Apoptosis resistance was accompanied by the absence of mitochondrial potential loss or cytochrome c translocation. r0 cells were also resistant to necrosis induced by reactive oxygen species (ROS) donors due to upregulation of antioxidant enzymes such as manganese superoxide dismutase. Mitochondria also has a close relationship with autophagy that plays a critical role in the turnover of senescent organelles or dysfunctional proteins and may be included in 'cell death' category. It was demonstrated that autophagy deficiency in insulin target tissues such as skeletal muscle induces mitochondrial stress response, which leads to the induction of FGF21 as a 'mitokine' and affects the whole body metabolism. These results show that mitochondria are not simply the power plants of cells generating ATP, but are closely related to several types of cell death and autophagy. Mitochondria affect various pathophysiological events related to diverse disorders such as cancer, metabolic disorders and aging. PMID:27100503

  18. Lysosomal photodamage induces cell death via mitochondrial apoptotic pathway

    NASA Astrophysics Data System (ADS)

    Liu, Lei; Wang, Xian-wang; Li, Hui

    2009-11-01

    Lysosomal photosensitizers have been used in photodynamic therapy (PDT). Combination of such photosensitizers and light causes lysosomal photodamage, inducing cell death. The lysosomal disruption can lead to apoptosis but its signaling pathways remain to be elucidated. In this study, we selected N-aspartyl chlorin e6 (NPe6), an effective photosensitizer which preferentially accumulates in lysosomes, to study the mechanism of apoptosis caused by lysosomal photodamage. Apoptosis in living human lung adenocarcinoma cells treated by NPe6-PDT was studied using real-time single-cell analysis. In this study, the fluorescence probes Cyto c-GFP and DsRed-Mit were used to detect the spatial and temporal changes of cytochrome c in real-time in sub-cell level; the Rhodamine 123 dyes were used to monitor the changes of mitochondrial membrane potential. The results showed that, after PDT treatment,the mitochondrial membrane potential decreased, and cytochrome c released from mitochondria; The caspase-3 was activated obviously. These results suggested that lysosomal photodamage activates mitochondrial apoptotic pathway to induce cell death.

  19. The essential role of evasion from cell death in cancer

    PubMed Central

    Kelly, Gemma; Strasser, Andreas

    2011-01-01

    The link between evasion of apoptosis and the development of cellular hyperplasia and ultimately cancer is implicitly clear if one considers how many cells are produced each day and, hence, how many cells must die to make room for the new ones (reviewed in (Raff, 1996)). Furthermore, cells are frequently experiencing noxious stimuli that can cause lesions in their DNA and faults in DNA replication can occur during cellular proliferation. Such DNA damage needs to be repaired efficiently or cells with irreparable damage must be killed to prevent subsequent division of aberrant cells that may fuel tumorigenesis (reviewed in (Weinberg, 2007)). The detection of genetic lesions in human cancers that activate pro-survival genes or disable pro-apoptotic genes have provided the first evidence that defects in programmed cell death can cause cancer (Tagawa et al., 2005; Tsujimoto et al., 1984; Vaux et al., 1988) and this concept was proven by studies with genetically modified mice (Egle et al., 2004b; Strasser et al., 1990a). It is therefore now widely accepted that evasion of apoptosis is a requirement for both neoplastic transformation and sustained growth of cancer cells (reviewed in (Cory and Adams, 2002; Hanahan and Weinberg, 2000; Weinberg, 2007)). Importantly, apoptosis is also a major contributor to anti-cancer therapy induced killing of tumor cells (reviewed in (Cory and Adams, 2002; Cragg et al., 2009)). Consequently, a detailed understanding of apoptotic cell death will help to better comprehend the complexities of tumorigenesis and should assist with the development of improved targeted therapies for cancer based on the direct activation of the apoptotic machinery (reviewed in (Lessene et al., 2008)). PMID:21704830

  20. Cell Death Control by Matrix Metalloproteinases1[OPEN

    PubMed Central

    Zimmermann, Dirk; Sieferer, Elke; Pfannstiel, Jens

    2016-01-01

    In contrast to mammalian matrix metalloproteinases (MMPs) that play important roles in the remodeling of the extracellular matrix in animals, the proteases responsible for dynamic modifications of the plant cell wall are largely unknown. A possible involvement of MMPs was addressed by cloning and functional characterization of Sl2-MMP and Sl3-MMP from tomato (Solanum lycopersicum). The two tomato MMPs were found to resemble mammalian homologs with respect to gelatinolytic activity, substrate preference for hydrophobic amino acids on both sides of the scissile bond, and catalytic properties. In transgenic tomato seedlings silenced for Sl2/3-MMP expression, necrotic lesions were observed at the base of the hypocotyl. Cell death initiated in the epidermis and proceeded to include outer cortical cell layers. In later developmental stages, necrosis spread, covering the entire stem and extending into the leaves of MMP-silenced plants. The subtilisin-like protease P69B was identified as a substrate of Sl2- and Sl3-MMP. P69B was shown to colocalize with Sl-MMPs in the apoplast of the tomato hypocotyl, it exhibited increased stability in transgenic plants silenced for Sl-MMP activity, and it was cleaved and inactivated by Sl-MMPs in vitro. The induction of cell death in Sl2/3-MMP-silenced plants depended on P69B, indicating that Sl2- and Sl3-MMP act upstream of P69B in an extracellular proteolytic cascade that contributes to the regulation of cell death in tomato. PMID:27208293

  1. Autophagy Protects Against Aminochrome-Induced Cell Death in Substantia Nigra-Derived Cell Line

    PubMed Central

    Paris, Irmgard; Muñoz, Patricia; Huenchuguala, Sandro; Couve, Eduardo; Sanders, Laurie H.; Greenamyre, John Timothy; Caviedes, Pablo; Segura-Aguilar, Juan

    2011-01-01

    Aminochrome, the precursor of neuromelanin, has been proposed to be involved in the neurodegeneration neuromelanin-containing dopaminergic neurons in Parkinson’s disease. We aimed to study the mechanism of aminochrome-dependent cell death in a cell line derived from rat substantia nigra. We found that aminochrome (50μM), in the presence of NAD(P)H-quinone oxidoreductase, EC 1.6.99.2 (DT)-diaphorase inhibitor dicoumarol (DIC) (100μM), induces significant cell death (62 ± 3%; p < 0.01), increase in caspase-3 activation (p < 0.001), release of cytochrome C, disruption of mitochondrial membrane potential (p < 0.01), damage of mitochondrial DNA, damage of mitochondria determined with transmission electron microscopy, a dramatic morphological change characterized as cell shrinkage, and significant increase in number of autophagic vacuoles. To determine the role of autophagy on aminochrome-induced cell death, we incubated the cells in the presence of vinblastine and rapamycin. Interestingly, 10μM vinblastine induces a 5.9-fold (p < 0.001) and twofold (p < 0.01) significant increase in cell death when the cells were incubated with 30μM aminochrome in the absence and presence of DIC, respectively, whereas 10μM rapamycin preincubated 24 h before addition of 50μM aminochrome in the absence and the presence of 100μM DIC induces a significant decrease (p < 0.001) in cell death. In conclusion, autophagy seems to be an important protective mechanism against two different aminochrome-induced cell deaths that initially showed apoptotic features. The cell death induced by aminochrome when DT-diaphorase is inhibited requires activation of mitochondrial pathway, whereas the cell death induced by aminochrome alone requires inhibition of autophagy-dependent degrading of damaged organelles and recycling through lysosomes. PMID:21427056

  2. Combinatorial Strategies for the Induction of Immunogenic Cell Death

    PubMed Central

    Bezu, Lucillia; Gomes-da-Silva, Ligia C.; Dewitte, Heleen; Breckpot, Karine; Fucikova, Jitka; Spisek, Radek; Galluzzi, Lorenzo; Kepp, Oliver; Kroemer, Guido

    2015-01-01

    The term “immunogenic cell death” (ICD) is commonly employed to indicate a peculiar instance of regulated cell death (RCD) that engages the adaptive arm of the immune system. The inoculation of cancer cells undergoing ICD into immunocompetent animals elicits a specific immune response associated with the establishment of immunological memory. Only a few agents are intrinsically endowed with the ability to trigger ICD. These include a few chemotherapeutics that are routinely employed in the clinic, like doxorubicin, mitoxantrone, oxaliplatin, and cyclophosphamide, as well as some agents that have not yet been approved for use in humans. Accumulating clinical data indicate that the activation of adaptive immune responses against dying cancer cells is associated with improved disease outcome in patients affected by various neoplasms. Thus, novel therapeutic regimens that trigger ICD are urgently awaited. Here, we discuss current combinatorial approaches to convert otherwise non-immunogenic instances of RCD into bona fide ICD. PMID:25964783

  3. Subnanosecond electric pulses cause membrane permeabilization and cell death.

    PubMed

    Xiao, Shu; Guo, Siqi; Nesin, Vasyl; Heller, Richard; Schoenbach, Karl H

    2011-05-01

    Subnanosecond electric pulses (200 ps) at electric field intensities on the order of 20 kV/cm cause the death of B16.F10 murine melanoma cells when applied for minutes with a pulse repetition rate of 10 kHz. The lethal effect of the ultrashort pulses is found to be caused by a combination of thermal effects and electrical effects. Studies on the cellular level show increased transport across the membrane at much lower exposure times or number of pulses. Exposed to 2000 pulses, NG108 cells exhibit an increase in membrane conductance, but only allow transmembrane currents to flow, if the medium is positively biased with respect to the cell interior. This means that the cell membrane behaves like a rectifying diode. This increase in membrane conductance is a nonthermal process, since the temperature rise due to the pulsing is negligible.

  4. Ceramide metabolism regulates autophagy and apoptotic cell death induced by melatonin in liver cancer cells.

    PubMed

    Ordoñez, Raquel; Fernández, Anna; Prieto-Domínguez, Néstor; Martínez, Laura; García-Ruiz, Carmen; Fernández-Checa, José C; Mauriz, José L; González-Gallego, Javier

    2015-09-01

    Autophagy is a process that maintains homeostasis during stress, although it also contributes to cell death under specific contexts. Ceramides have emerged as important effectors in the regulation of autophagy, mediating the crosstalk with apoptosis. Melatonin induces apoptosis of cancer cells; however, its role in autophagy and ceramide metabolism has yet to be clearly elucidated. This study was aimed to evaluate the effect of melatonin administration on autophagy and ceramide metabolism and its possible link with melatonin-induced apoptotic cell death in hepatocarcinoma (HCC) cells. Melatonin (2 mm) transiently induced autophagy in HepG2 cells through JNK phosphorylation, characterized by increased Beclin-1 expression, p62 degradation, and LC3II and LAMP-2 colocalization, which translated in decreased cell viability. Moreover, ATG5 silencing sensitized HepG2 cells to melatonin-induced apoptosis, suggesting a dual role of autophagy in cell death. Melatonin enhanced ceramide levels through both de novo synthesis and acid sphingomyelinase (ASMase) stimulation. Serine palmitoyltransferase (SPT) inhibition with myriocin prevented melatonin-induced autophagy and ASMase inhibition with imipramine-impaired autophagy flux. However, ASMase inhibition partially protected HepG2 cells against melatonin, while SPT inhibition significantly enhanced cell death. Findings suggest a crosstalk between SPT-mediated ceramide generation and autophagy in protecting against melatonin, while specific ASMase-induced ceramide production participates in melatonin-mediated cell death. Thus, dual blocking of SPT and autophagy emerges as a potential strategy to potentiate the apoptotic effects of melatonin in liver cancer cells.

  5. Statins and Voriconazole Induce Programmed Cell Death in Acanthamoeba castellanii

    PubMed Central

    López-Arencibia, Atteneri; Sifaoui, Ines; Reyes-Batlle, María; Valladares, Basilio; Martínez-Carretero, Enrique; Piñero, José E.; Maciver, Sutherland K.; Lorenzo-Morales, Jacob

    2015-01-01

    Members of the genus Acanthamoeba are facultative pathogens of humans, causing a sight-threatening keratitis and a life-threatening encephalitis. In order to treat those infections properly, it is necessary to target the treatment not only to the trophozoite but also to the cyst. Furthermore, it may be advantageous to avoid parasite killing by necrosis, which may induce local inflammation. We must also avoid toxicity of host tissue. Many drugs which target eukaryotes are known to induce programmed cell death (PCD), but this process is poorly characterized in Acanthamoeba. Here, we study the processes of programmed cell death in Acanthamoeba, induced by several drugs, such as statins and voriconazole. We tested atorvastatin, fluvastatin, simvastatin, and voriconazole at the 50% inhibitory concentrations (IC50s) and IC90s that we have previously established. In order to evaluate this phenomenon, we investigated the DNA fragmentation, one of the main characteristics of PCD, with quantitative and qualitative techniques. Also, the changes related to phosphatidylserine exposure on the external cell membrane and cell permeability were studied. Finally, because caspases are key to PCD pathways, caspase activity was evaluated in Acanthamoeba. All the drugs assayed in this study induced PCD in Acanthamoeba. To the best of our knowledge, this is the first study where PCD induced by drugs is described quantitatively and qualitatively in Acanthamoeba. PMID:25733513

  6. Programmed cell death in C. elegans, mammals and plants.

    PubMed

    Lord, Christina E N; Gunawardena, Arunika H L A N

    2012-08-01

    Programmed cell death (PCD) is the regulated removal of cells within an organism and plays a fundamental role in growth and development in nearly all eukaryotes. In animals, the model organism Caenorhabditis elegans (C. elegans) has aided in elucidating many of the pathways involved in the cell death process. Various analogous PCD processes can also be found within mammalian PCD systems, including vertebrate limb development. Plants and animals also appear to share hallmarks of PCD, both on the cellular and molecular level. Cellular events visualized during plant PCD resemble those seen in animals including: nuclear condensation, DNA fragmentation, cytoplasmic condensation, and plasma membrane shrinkage. Recently the molecular mechanisms involved in plant PCD have begun to be elucidated. Although few regulatory proteins have been identified as conserved across all eukaryotes, molecular features such as the participation of caspase-like proteases, Bcl-2-like family members and mitochondrial proteins appear to be conserved between plant and animal systems. Transgenic expression of mammalian and C. elegans pro- and anti-apoptotic genes in plants has been observed to dramatically influence the regulatory pathways of plant PCD. Although these genes often show little to no sequence similarity they can frequently act as functional substitutes for one another, thus suggesting that action may be more important than sequence resemblance. Here we present a summary of these findings, focusing on the similarities, between mammals, C. elegans, and plants. An emphasis will be placed on the mitochondria and its role in the cell death pathway within each organism. Through the comparison of these systems on both a cellular and molecular level we can begin to better understand PCD in plant systems, and perhaps shed light on the pathways, which are controlling the process. This manuscript adds to the field of PCD in plant systems by profiling apoptotic factors, to scale on a protein

  7. Bifurcate effects of glucose on caspase-independent cell death during hypoxia

    SciTech Connect

    Aki, Toshihiko; Nara, Akina; Funakoshi, Takeshi; Uemura, Koichi

    2010-06-04

    We investigated the effect of glucose on hypoxic death of rat cardiomyocyte-derived H9c2 cells and found that there is an optimal glucose concentration for protection against hypoxic cell death. Hypoxic cell death in the absence of glucose is accompanied by rapid ATP depletion, release of apoptosis-inducing factor from mitochondria, and nuclear chromatin condensation, all of which are inhibited by glucose in a dose-dependent manner. In contrast, excessive glucose also induces hypoxic cell death that is not accompanied by these events, suggesting a change in the mode of cell death between hypoxic cells with and without glucose supplementation.

  8. Reduction of cardiac cell death after helium postconditioning in rats: transcriptional analysis of cell death and survival pathways.

    PubMed

    Oei, Gezina T M L; Heger, Michal; van Golen, Rowan F; Alles, Lindy K; Flick, Moritz; van der Wal, Allard C; van Gulik, Thomas M; Hollmann, Markus W; Preckel, Benedikt; Weber, Nina C

    2015-01-20

    Helium, a noble gas, has been used safely in humans. In animal models of regional myocardial ischemia/reperfusion (I/R) it was shown that helium conditioning reduces infarct size. Currently, it is not known how helium exerts its cytoprotective effects and which cell death/survival pathways are affected. The objective of this study, therefore, was to investigate the cell protective effects of helium postconditioning by PCR array analysis of genes involved in necrosis, apoptosis and autophagy. Male rats were subjected to 25 min of ischemia and 5, 15 or 30 min of reperfusion. Semiquantitative histological analysis revealed that 15 min of helium postconditioning reduced the extent of I/R-induced cell damage. This effect was not observed after 5 and 30 min of helium postconditioning. Analysis of the differential expression of genes showed that 15 min of helium postconditioning mainly caused upregulation of genes involved in autophagy and inhibition of apoptosis versus I/R alone. The results suggest that the cytoprotective effects of helium inhalation may be caused by a switch from pro-cell-death signaling to activation of cell survival mechanisms, which appears to affect a wide range of pathways.

  9. Reduction of Cardiac Cell Death after Helium Postconditioning in Rats: Transcriptional Analysis of Cell Death and Survival Pathways

    PubMed Central

    Oei, Gezina TML; Heger, Michal; van Golen, Rowan F; Alles, Lindy K; Flick, Moritz; van der Wal, Allard C; van Gulik, Thomas M; Hollmann, Markus W; Preckel, Benedikt; Weber, Nina C

    2014-01-01

    Helium, a noble gas, has been used safely in humans. In animal models of regional myocardial ischemia/reperfusion (I/R) it was shown that helium conditioning reduces infarct size. Currently, it is not known how helium exerts its cytoprotective effects and which cell death/survival pathways are affected. The objective of this study, therefore, was to investigate the cell protective effects of helium postconditioning by PCR array analysis of genes involved in necrosis, apoptosis and autophagy. Male rats were subjected to 25 min of ischemia and 5, 15 or 30 min of reperfusion. Semiquantitative histological analysis revealed that 15 min of helium postconditioning reduced the extent of I/R-induced cell damage. This effect was not observed after 5 and 30 min of helium postconditioning. Analysis of the differential expression of genes showed that 15 min of helium postconditioning mainly caused upregulation of genes involved in autophagy and inhibition of apoptosis versus I/R alone. The results suggest that the cytoprotective effects of helium inhalation may be caused by a switch from pro-cell-death signaling to activation of cell survival mechanisms, which appears to affect a wide range of pathways. PMID:25171109

  10. Hydralazine rescues PC12 cells from acrolein-mediated death.

    PubMed

    Liu-Snyder, Peishan; Borgens, Richard Ben; Shi, Riyi

    2006-07-01

    Acrolein, a major lipid peroxidation product, has been associated with both CNS trauma and neurodegenerative diseases. Because of its long half-life, acrolein is a potent endogenous toxin capable of killing healthy cells during the secondary injury process. Traditionally, attempts to intervene in the process of progressive cell death after the primary injury have included scavenging reactive oxygen species (so-called free radicals). The animal data supporting such an approach have generally been positive, but all human clinical trials attempting a similar outcome in human CNS injury have failed. New drugs that might reduce toxicity by scavenging the products of lipid peroxidation present a promising, and little investigated, therapeutic approach. Hydralazine, a well-known treatment for hypertension, has been reported to react with acrolein, forming hydrazone in cell-free systems. In the companion paper, we have established an acrolein-mediated cell injury model using PC12 cells in vitro. Here we test the hypothesis that the formation of hydrazone adducts with acrolein is able to reduce acrolein toxicity and spare a significant percentage of the population of PC12 cells from death. Concentrations of approximately 1 mM of this aldehyde scavenger can rescue over 80% of the population of PC12 cells. This study provides a basis for a new pharmacological treatment to reduce the effects of secondary injury in the damaged and/or diseased nervous system. In particular, we describe the need for new drugs that possess aldehyde scavenging properties but do not interfere with the regulation of blood pressure.

  11. Apoptotic tubular cell death during acute renal allograft rejection.

    PubMed

    Wever, P C; Aten, J; Rentenaar, R J; Hack, C E; Koopman, G; Weening, J J; ten Berge, I J

    1998-01-01

    Tubular cells are important targets during acute renal allograft rejection and induction of apoptosis might be a mechanism of tubular cell destruction. Susceptibility to induction of apoptosis is regulated by the homologous Bcl-2 and Bax proteins. Expression of Bcl-2 and Bax is regulated by p53, which down-regulates expression of Bcl-2, while simultaneously up-regulating expression of Bax. We studied apoptotic tubular cell death in 10 renal allograft biopsies from transplant recipients with acute rejection by in situ end-labelling and the DNA-binding fluorochrome propidium iodide. Tubular expression of p53, Bcl-2 and Bax was studies by immunohistochemistry. Five renal allograft biopsies from transplant recipients with uncomplicated clinical course and histologically normal renal tissue present in nephrectomy specimens from 4 patients with renal adenocarcinoma served as control specimens. Apoptotic cells and apoptotic bodies were detected in tubular epithelia and tubular lumina in 9 out of 10 acute rejection biopsies. In control renal tissue, apoptotic cells were detected in 1 biopsy only. Compared to control renal tissue, acute renal allograft rejection was, furthermore, associated with a shift in the ratio of Bcl-2 to Bax in favour of Bax in tubular epithelia and increased expression of p53 in tubular nuclei. These observations demonstrate that apoptosis contributes in part to tubular cell destruction during acute renal allograft rejection. In accordance, the shift in the ratio of Bcl-2 to Bax in favour of Bax indicates increased susceptibility of tubular epithelia to induction of apoptosis. The expression of p53 in tubular nuclei during acute renal allograft rejection indicates the presence of damaged DNA, which can be important in initiation of part of the observed apoptosis. These findings elucidate part of the mechanisms controlling apoptotic tubular cell death during acute renal allograft rejection.

  12. Effect of formaldehyde on cell proliferation and death.

    PubMed

    Szende, Béla; Tyihák, Erno

    2010-12-01

    Formaldehyde (HCHO) may reach living organisms as an exogenous agent or produced within cells. The so-called formaldehydogenic compounds like S-adenosyl-L-methionine, N-hydroxymethyl-L-arginine, 1'-methyl ascorbigen, methanol, E-N-trimethyl lysine and methylamine are special exogenous sources of HCHO. Endogenous HCHO can be formed from hydroxymethyl groups during enzymatic methylation and demethylation processes. HCHO, as a highly reactive compound, is considered to be involved in the induction of apoptosis, consequently in the pathogenesis of atherosclerosis and neurodegenerative processes. The biological action of HCHO is dose-dependent. In vitro studies on tumour cell and endothelial cell cultures showed that HCHO in the concentration of 10.0 mM caused necrotic cell death, 1.0 mM resulted in enhanced apoptosis and reduced mitotic activity, while 0.5 and 0.1 mM enhanced cell proliferation and reduced apoptotic activity. Among formaldehydogenic compounds N-hydroxymethyl-L-arginine, 1'-methyl ascorbigen and the HCHO donor resveratrol may be considered as potential inhibitors of cell proliferation. Endogenous HCHO in plants apparently play a role in regulation of apoptosis and cell proliferation. The genotoxic and carcinogentic effects of HCHO is due to production of DNA-protein cross-links. Low doses of HCHO, reducing apoptotic activity may also accumulate cells with such cross-links. Experimental data point to the possible therapeutic use of methylated lysine residues and methylated arginine residues in the case of neoplasms.

  13. Peruvoside, a Cardiac Glycoside, Induces Primitive Myeloid Leukemia Cell Death.

    PubMed

    Feng, Qian; Leong, Wa Seng; Liu, Liang; Chan, Wai-In

    2016-01-01

    Despite the available chemotherapy and treatment, leukemia remains a difficult disease to cure due to frequent relapses after treatment. Among the heterogeneous leukemic cells, a rare population referred as the leukemic stem cell (LSC), is thought to be responsible for relapses and drug resistance. Cardiac glycosides (CGs) have been used in treating heart failure despite its toxicity. Recently, increasing evidence has demonstrated its new usage as a potential anti-cancer drug. Ouabain, one of the CGs, specifically targeted CD34⁺CD38(-) leukemic stem-like cells, but not the more mature CD34⁺CD38⁺ leukemic cells, making this type of compounds a potential treatment for leukemia. In search of other potential anti-leukemia CGs, we found that Peruvoside, a less studied CG, is more effective than Ouabain and Digitoxin at inducing cell death in primitive myeloid leukemia cells without obvious cytotoxicity on normal blood cells. Similar to Ouabain and Digitoxin, Peruvoside also caused cell cycle arrest at G₂/M stage. It up-regulates CDKN1A expression and activated the cleavage of Caspase 3, 8 and PARP, resulting in apoptosis. Thus, Peruvoside showed potent anti-leukemia effect, which may serve as a new anti-leukemia agent in the future. PMID:27110755

  14. Cell Arrest and Cell Death in Mammalian Preimplantation Development: Lessons from the Bovine Model

    PubMed Central

    Leidenfrost, Sandra; Boelhauve, Marc; Reichenbach, Myriam; Güngör, Tuna; Reichenbach, Horst-Dieter; Sinowatz, Fred; Wolf, Eckhard; Habermann, Felix A.

    2011-01-01

    Background The causes, modes, biological role and prospective significance of cell death in preimplantation development in humans and other mammals are still poorly understood. Early bovine embryos represent a very attractive experimental model for the investigation of this fundamental and important issue. Methods and Findings To obtain reference data on the temporal and spatial occurrence of cell death in early bovine embryogenesis, three-dimensionally preserved embryos of different ages and stages of development up to hatched blastocysts were examined in toto by confocal laser scanning microscopy. In parallel, transcript abundance profiles for selected apoptosis-related genes were analyzed by real-time reverse transcriptase-polymerase chain reaction. Our study documents that in vitro as well as in vivo, the first four cleavage cycles are prone to a high failure rate including different types of permanent cell cycle arrest and subsequent non-apoptotic blastomere death. In vitro produced and in vivo derived blastocysts showed a significant incidence of cell death in the inner cell mass (ICM), but only in part with morphological features of apoptosis. Importantly, transcripts for CASP3, CASP9, CASP8 and FAS/FASLG were not detectable or found at very low abundances. Conclusions In vitro and in vivo, errors and failures of the first and the next three cleavage divisions frequently cause immediate embryo death or lead to aberrant subsequent development, and are the main source of developmental heterogeneity. A substantial occurrence of cell death in the ICM even in fast developing blastocysts strongly suggests a regular developmentally controlled elimination of cells, while the nature and mechanisms of ICM cell death are unclear. Morphological findings as well as transcript levels measured for important apoptosis-related genes are in conflict with the view that classical caspase-mediated apoptosis is the major cause of cell death in early bovine development. PMID

  15. Trial Watch: Immunogenic cell death inducers for anticancer chemotherapy

    PubMed Central

    Pol, Jonathan; Vacchelli, Erika; Aranda, Fernando; Castoldi, Francesca; Eggermont, Alexander; Cremer, Isabelle; Sautès-Fridman, Catherine; Fucikova, Jitka; Galon, Jérôme; Spisek, Radek; Tartour, Eric; Zitvogel, Laurence; Kroemer, Guido; Galluzzi, Lorenzo

    2015-01-01

    The term “immunogenic cell death” (ICD) is now employed to indicate a functionally peculiar form of apoptosis that is sufficient for immunocompetent hosts to mount an adaptive immune response against dead cell-associated antigens. Several drugs have been ascribed with the ability to provoke ICD when employed as standalone therapeutic interventions. These include various chemotherapeutics routinely employed in the clinic (e.g., doxorubicin, epirubicin, idarubicin, mitoxantrone, bleomycin, bortezomib, cyclophosphamide and oxaliplatin) as well as some anticancer agents that are still under preclinical or clinical development (e.g., some microtubular inhibitors of the epothilone family). In addition, a few drugs are able to convert otherwise non-immunogenic instances of cell death into bona fide ICD, and may therefore be employed as chemotherapeutic adjuvants within combinatorial regimens. This is the case of cardiac glycosides, like digoxin and digitoxin, and zoledronic acid. Here, we discuss recent developments on anticancer chemotherapy based on ICD inducers. PMID:26137404

  16. Activated microglia cause reversible apoptosis of pheochromocytoma cells, inducing their cell death by phagocytosis.

    PubMed

    Hornik, Tamara C; Vilalta, Anna; Brown, Guy C

    2016-01-01

    Some apoptotic processes, such as phosphatidylserine exposure, are potentially reversible and do not necessarily lead to cell death. However, phosphatidylserine exposure can induce phagocytosis of a cell, resulting in cell death by phagocytosis: phagoptosis. Phagoptosis of neurons by microglia might contribute to neuropathology, whereas phagoptosis of tumour cells by macrophages might limit cancer. Here, we examined the mechanisms by which BV-2 microglia killed co-cultured pheochromocytoma (PC12) cells that were either undifferentiated or differentiated into neuronal cells. We found that microglia activated by lipopolysaccharide rapidly phagocytosed PC12 cells. Activated microglia caused reversible phosphatidylserine exposure on and reversible caspase activation in PC12 cells, and caspase inhibition prevented phosphatidylserine exposur and decreased subsequent phagocytosis. Nitric oxide was necessary and sufficient to induce the reversible phosphatidylserine exposure and phagocytosis. The PC12 cells were not dead at the time they were phagocytised, and inhibition of their phagocytosis left viable cells. Cell loss was inhibited by blocking phagocytosis mediated by phosphatidylserine, MFG-E8, vitronectin receptors or P2Y6 receptors. Thus, activated microglia can induce reversible apoptosis of target cells, which is insufficient to cause apoptotic cell death, but sufficient to induce their phagocytosis and therefore cell death by phagoptosis.

  17. Mitochondrial dynamics and cell death in heart failure.

    PubMed

    Marín-García, José; Akhmedov, Alexander T

    2016-03-01

    The highly regulated processes of mitochondrial fusion (joining), fission (division) and trafficking, collectively called mitochondrial dynamics, determine cell-type specific morphology, intracellular distribution and activity of these critical organelles. Mitochondria are critical for cardiac function, while their structural and functional abnormalities contribute to several common cardiovascular diseases, including heart failure (HF). The tightly balanced mitochondrial fusion and fission determine number, morphology and activity of these multifunctional organelles. Although the intracellular architecture of mature cardiomyocytes greatly restricts mitochondrial dynamics, this process occurs in the adult human heart. Fusion and fission modulate multiple mitochondrial functions, ranging from energy and reactive oxygen species production to Ca(2+) homeostasis and cell death, allowing the heart to respond properly to body demands. Tightly controlled balance between fusion and fission is of utmost importance in the high energy-demanding cardiomyocytes. A shift toward fission leads to mitochondrial fragmentation, while a shift toward fusion results in the formation of enlarged mitochondria and in the fusion of damaged mitochondria with healthy organelles. Mfn1, Mfn2 and OPA1 constitute the core machinery promoting mitochondrial fusion, whereas Drp1, Fis1, Mff and MiD49/51 are the core components of fission machinery. Growing evidence suggests that fusion/fission factors in adult cardiomyocytes play essential noncanonical roles in cardiac development, Ca(2+) signaling, mitochondrial quality control and cell death. Impairment of this complex circuit causes cardiomyocyte dysfunction and death contributing to heart injury culminating in HF. Pharmacological targeting of components of this intricate network may be a novel therapeutic modality for HF treatment. PMID:26872674

  18. Comparative analysis of programmed cell death pathways in filamentous fungi

    PubMed Central

    Fedorova, Natalie D; Badger, Jonathan H; Robson, Geoff D; Wortman, Jennifer R; Nierman, William C

    2005-01-01

    Background Fungi can undergo autophagic- or apoptotic-type programmed cell death (PCD) on exposure to antifungal agents, developmental signals, and stress factors. Filamentous fungi can also exhibit a form of cell death called heterokaryon incompatibility (HI) triggered by fusion between two genetically incompatible individuals. With the availability of recently sequenced genomes of Aspergillus fumigatus and several related species, we were able to define putative components of fungi-specific death pathways and the ancestral core apoptotic machinery shared by all fungi and metazoa. Results Phylogenetic profiling of HI-associated proteins from four Aspergilli and seven other fungal species revealed lineage-specific protein families, orphan genes, and core genes conserved across all fungi and metazoa. The Aspergilli-specific domain architectures include NACHT family NTPases, which may function as key integrators of stress and nutrient availability signals. They are often found fused to putative effector domains such as Pfs, SesB/LipA, and a newly identified domain, HET-s/LopB. Many putative HI inducers and mediators are specific to filamentous fungi and not found in unicellular yeasts. In addition to their role in HI, several of them appear to be involved in regulation of cell cycle, development and sexual differentiation. Finally, the Aspergilli possess many putative downstream components of the mammalian apoptotic machinery including several proteins not found in the model yeast, Saccharomyces cerevisiae. Conclusion Our analysis identified more than 100 putative PCD associated genes in the Aspergilli, which may help expand the range of currently available treatments for aspergillosis and other invasive fungal diseases. The list includes species-specific protein families as well as conserved core components of the ancestral PCD machinery shared by fungi and metazoa. PMID:16336669

  19. Alternative flow cytometry strategies to analyze stem cells and cell death in planarians.

    PubMed

    Peiris, Tanuja Harshani; García-Ojeda, Marcos E; Oviedo, Néstor J

    2016-04-01

    Planarians possess remarkable stem cell populations that continuously support cellular turnover and are instrumental in the regeneration of tissues upon injury. Cellular turnover and tissue regeneration in planarians rely on the proper integration of local and systemic signals that regulate cell proliferation and cell death. Thus, understanding the signals controlling cellular proliferation and cell death in planarians could provide valuable insights for maintenance of adult body homeostasis and the biology of regeneration. Flow cytometry techniques have been utilized widely to identify, isolate, and characterize planarian stem cell populations. We developed alternative flow cytometry strategies that reduce the number of reagents and the time of sample preparation to analyze stem cells and cell death in planarians. The sensitivity of these methods is validated with functional studies using RNA interference and treatment with  γ irradiation or stressful conditions that are known to trigger cell death. Altogether, we provide a community resource intended to minimize adverse effects during ex vivo studies of stem cells and cell death in planarians.

  20. Alternative flow cytometry strategies to analyze stem cells and cell death in planarians

    PubMed Central

    Peiris, Tanuja Harshani; García‐Ojeda, Marcos E.

    2016-01-01

    Abstract Planarians possess remarkable stem cell populations that continuously support cellular turnover and are instrumental in the regeneration of tissues upon injury. Cellular turnover and tissue regeneration in planarians rely on the proper integration of local and systemic signals that regulate cell proliferation and cell death. Thus, understanding the signals controlling cellular proliferation and cell death in planarians could provide valuable insights for maintenance of adult body homeostasis and the biology of regeneration. Flow cytometry techniques have been utilized widely to identify, isolate, and characterize planarian stem cell populations. We developed alternative flow cytometry strategies that reduce the number of reagents and the time of sample preparation to analyze stem cells and cell death in planarians. The sensitivity of these methods is validated with functional studies using RNA interference and treatment with  γ irradiation or stressful conditions that are known to trigger cell death. Altogether, we provide a community resource intended to minimize adverse effects during ex vivo studies of stem cells and cell death in planarians. PMID:27307993

  1. Sulbutiamine counteracts trophic factor deprivation induced apoptotic cell death in transformed retinal ganglion cells.

    PubMed

    Kang, Kui Dong; Majid, Aman Shah Abdul; Kim, Kyung-A; Kang, Kyungsu; Ahn, Hong Ryul; Nho, Chu Won; Jung, Sang Hoon

    2010-11-01

    Sulbutiamine is a highly lipid soluble synthetic analogue of vitamin B(1) and is used clinically for the treatment of asthenia. The aim of our study was to demonstrate whether sulbutiamine is able to attenuate trophic factor deprivation induced cell death to transformed retinal ganglion cells (RGC-5). Cells were subjected to serum deprivation for defined periods and sulbutiamine at different concentrations was added to the cultures. Various procedures (e.g. cell viability assays, apoptosis assay, reactive oxygen species analysis, Western blot analysis, flow cytometric analysis, glutathione (GSH) and glutathione-S-transferase (GST) measurement) were used to demonstrate the effect of sulbutiamine. Sulbutiamine dose-dependently attenuated apoptotic cell death induced by serum deprivation and stimulated GSH and GST activity. Moreover, sulbutiamine decreased the expression of cleaved caspase-3 and AIF. This study demonstrates for the first time that sulbutiamine is able to attenuate trophic factor deprivation induced apoptotic cell death in neuronal cells in culture. PMID:20809085

  2. Regulation of Cell Death by IAPs and Their Antagonists.

    PubMed

    Vasudevan, Deepika; Ryoo, Hyung Don

    2015-01-01

    Inhibitors of apoptosis (IAPs) family of genes encode baculovirus IAP-repeat domain-containing proteins with antiapoptotic function. These proteins also contain RING or UBC domains and act by binding to major proapoptotic factors and ubiquitylating them. High levels of IAPs inhibit caspase-mediated apoptosis. For these cells to undergo apoptosis, IAP function must be neutralized by IAP-antagonists. Mammalian IAP knockouts do not exhibit obvious developmental phenotypes, but the cells are more sensitized to apoptosis in response to injury. Loss of the mammalian IAP-antagonist ARTS results in reduced stem cell apoptosis. In addition to the antiapoptotic properties, IAPs regulate the innate immune response, and the loss of IAP function in humans is associated with immunodeficiency. The roles of IAPs in Drosophila apoptosis regulation are more apparent, where the loss of IAP1, or the expression of IAP-antagonists in Drosophila cells, is sufficient to trigger apoptosis. In this organism, apoptosis as a fate is conferred by the transcriptional induction of the IAP-antagonists. Many signaling pathways often converge on shared enhancer regions of IAP-antagonists. Cell death sensitivity is further regulated by posttranscriptional mechanisms, including those regulated by kinases, miRs, and ubiquitin ligases. These mechanisms are employed to eliminate damaged or virus-infected cells, limit neuroblast (neural stem cell) numbers, generate neuronal diversity, and sculpt tissue morphogenesis.

  3. Cell Death and Tissue Remodeling in Planarian Regeneration

    PubMed Central

    Pellettieri, Jason; Fitzgerald, Patrick; Watanabe, Shigeki; Mancuso, Joel; Green, Douglas R.; Alvarado, Alejandro Sánchez

    2010-01-01

    Many long-lived organisms, including humans, can regenerate some adult tissues lost to physical injury or disease. Much of the previous research on mechanisms of regeneration has focused on adult stem cells, which give rise to new tissue necessary for the replacement of missing body parts. Here we report that apoptosis of differentiated cells complements stem cell division during regeneration in the planarian Schmidtea mediterranea. Specifically, we developed a whole-mount TUNEL assay that allowed us to document two dramatic increases in the rate of apoptosis following amputation – an intial localized response near the wound site and a subsequent systemic response that varies in magnitude depending on the type of fragment examined. The latter cell death response can be induced in uninjured organs, occurs in the absence of planarian stem cells, and can also be triggered by prolonged starvation. Taken together, our results implicate apoptosis in the restoration of proper anatomical scale and proportion through remodeling of existing tissues. We also report results from initial mechanistic studies of apoptosis in planarians, which revealed that a S. mediterranea homolog of the antiapoptotic gene BCL2 is required for cell survival in adult animals. We propose that apoptosis is a central mechanism working in concert with stem cell division to restore anatomical form and function during metazoan regeneration. PMID:19766622

  4. Isogambogenic acid induces apoptosis-independent autophagic cell death in human non-small-cell lung carcinoma cells.

    PubMed

    Yang, Jianhong; Zhou, Yongzhao; Cheng, Xia; Fan, Yi; He, Shichao; Li, Shucai; Ye, Haoyu; Xie, Caifeng; Wu, Wenshuang; Li, Chunyan; Pei, Heying; Li, Luyuan; Wei, Zhe; Peng, Aihua; Wei, Yuquan; Li, Weimin; Chen, Lijuan

    2015-01-09

    To overcome drug resistance caused by apoptosis deficiency in patients with non-small cell lung carcinoma (NSCLC), there is a need to identify other means of triggering apoptosis-independent cancer cell death. We are the first to report that isogambogenic acid (iso-GNA) can induce apoptosis-independent autophagic cell death in human NSCLC cells. Several features of the iso-GNA-treated NSCLC cells indicated that iso-GNA induced autophagic cell death. First, there was no evidence of apoptosis or cleaved caspase 3 accumulation and activation. Second, iso-GNA treatment induced the formation of autophagic vacuoles, increased LC3 conversion, caused the appearance of autophagosomes and increased the expression of autophagy-related proteins. These findings provide evidence that iso-GNA induces autophagy in NSCLC cells. Third, iso-GNA-induced cell death was inhibited by autophagic inhibitors or by selective ablation of Atg7 and Beclin 1 genes. Furthermore, the mTOR inhibitor rapamycin increased iso-GNA-induced cell death by enhancing autophagy. Finally, a xenograft model provided additional evidence that iso-GNA exhibited anticancer effect through inducing autophagy-dependent cell death in NSCLC cells. Taken together, our results demonstrated that iso-GNA exhibited an anticancer effect by inducing autophagy-dependent cell death in NSCLC cells, which may be an effective chemotherapeutic agent that can be used against NSCLC in a clinical setting.

  5. Isogambogenic acid induces apoptosis-independent autophagic cell death in human non-small-cell lung carcinoma cells

    PubMed Central

    Yang, Jianhong; Zhou, Yongzhao; Cheng, Xia; Fan, Yi; He, Shichao; Li, Shucai; Ye, Haoyu; Xie, Caifeng; Wu, Wenshuang; Li, Chunyan; Pei, Heying; Li, Luyuan; Wei, Zhe; Peng, Aihua; Wei, Yuquan; Li, Weimin; Chen, Lijuan

    2015-01-01

    To overcome drug resistance caused by apoptosis deficiency in patients with non-small cell lung carcinoma (NSCLC), there is a need to identify other means of triggering apoptosis-independent cancer cell death. We are the first to report that isogambogenic acid (iso-GNA) can induce apoptosis-independent autophagic cell death in human NSCLC cells. Several features of the iso-GNA-treated NSCLC cells indicated that iso-GNA induced autophagic cell death. First, there was no evidence of apoptosis or cleaved caspase 3 accumulation and activation. Second, iso-GNA treatment induced the formation of autophagic vacuoles, increased LC3 conversion, caused the appearance of autophagosomes and increased the expression of autophagy-related proteins. These findings provide evidence that iso-GNA induces autophagy in NSCLC cells. Third, iso-GNA-induced cell death was inhibited by autophagic inhibitors or by selective ablation of Atg7 and Beclin 1 genes. Furthermore, the mTOR inhibitor rapamycin increased iso-GNA-induced cell death by enhancing autophagy. Finally, a xenograft model provided additional evidence that iso-GNA exhibited anticancer effect through inducing autophagy-dependent cell death in NSCLC cells. Taken together, our results demonstrated that iso-GNA exhibited an anticancer effect by inducing autophagy-dependent cell death in NSCLC cells, which may be an effective chemotherapeutic agent that can be used against NSCLC in a clinical setting. PMID:25571970

  6. Atg3 Overexpression Enhances Bortezomib-Induced Cell Death in SKM-1 Cell

    PubMed Central

    Wang, Qian; Zhang, Jing; Zhu, Chen; Zhang, Lu; Xu, Xiaoping

    2016-01-01

    Background Myelodysplastic syndrome (MDS) is a group of heterogeneous hematopoietic stem cell malignancies with a high risk of transformation into acute myeloid leukemia (AML). Clonal evolutions are significantly associated with transformation to AML. According to a gene expression microarray, atg3 is downregulated in MDS patients progressing to leukemia, but less is known about the function of Atg3 in the survival and death of MSD/AML cells. Moreover, the role of autophagy as a result of bortezomib treatment is controversial. The current study was designed to investigate the function of Atg3 in SKM-1 cells and to study the effect of Atg3 on cell viability and cell death following bortezomib treatment. Methods Four leukemia cell lines (SKM-1, THP-1, NB4 and K562) and two healthy patients’ bone marrow cells were analyzed for Atg3 expression via qRT-PCR and Western blotting analysis. The role of Atg3 in SKM-1 cell survival and cell death was analyzed by CCK-8 assay, trypan blue exclusion assay, DAPI staining and Annexin V/PI dual staining with or without bortezomib treatment. Western blotting analysis was used to detect proteins in autophagic and caspase signaling pathways. Electron microscopy was used to observe ultrastructural changes after Atg3 overexpression. Results Downregulation of Atg3 expression was detected in four leukemia cell lines compared with healthy bone marrow cells. Atg3 mRNA was significantly decreased in MDS patients’ bone marrow cells. Overexpression of Atg3 in SKM-1 cells resulted in AKT-mTOR-dependent autophagy, a significant reduction in cell proliferation and increased cell death, which could be overcome by the autophagy inhibitor 3-MA. SKM-1 cells overexpressing Atg3 were hypersensitive to bortezomib treatment at different concentrations via autophagic cell death and enhanced sensitivity to apoptosis in the SKM-1 cell line. Following treatment with 3-MA, the sensitivity of Atg3-overexpressing cells to bortezomib treatment was reduced

  7. Regulation of cell death receptor S-nitrosylation and apoptotic signaling by Sorafenib in hepatoblastoma cells☆

    PubMed Central

    Rodríguez-Hernández, A.; Navarro-Villarán, E.; González, R.; Pereira, S.; Soriano-De Castro, L.B.; Sarrias-Giménez, A.; Barrera-Pulido, L.; Álamo-Martínez, J.M.; Serrablo-Requejo, A.; Blanco-Fernández, G.; Nogales-Muñoz, A.; Gila-Bohórquez, A.; Pacheco, D.; Torres-Nieto, M.A.; Serrano-Díaz-Canedo, J.; Suárez-Artacho, G.; Bernal-Bellido, C.; Marín-Gómez, L.M.; Barcena, J.A.; Gómez-Bravo, M.A.; Padilla, C.A.; Padillo, F.J.; Muntané, J.

    2015-01-01

    Nitric oxide (NO) plays a relevant role during cell death regulation in tumor cells. The overexpression of nitric oxide synthase type III (NOS-3) induces oxidative and nitrosative stress, p53 and cell death receptor expression and apoptosis in hepatoblastoma cells. S-nitrosylation of cell death receptor modulates apoptosis. Sorafenib is the unique recommended molecular-targeted drug for the treatment of patients with advanced hepatocellular carcinoma. The present study was addressed to elucidate the potential role of NO during Sorafenib-induced cell death in HepG2 cells. We determined the intra- and extracellular NO concentration, cell death receptor expression and their S-nitrosylation modifications, and apoptotic signaling in Sorafenib-treated HepG2 cells. The effect of NO donors on above parameters has also been determined. Sorafenib induced apoptosis in HepG2 cells. However, low concentration of the drug (10 nM) increased cell death receptor expression, as well as caspase-8 and -9 activation, but without activation of downstream apoptotic markers. In contrast, Sorafenib (10 µM) reduced upstream apoptotic parameters but increased caspase-3 activation and DNA fragmentation in HepG2 cells. The shift of cell death signaling pathway was associated with a reduction of S-nitrosylation of cell death receptors in Sorafenib-treated cells. The administration of NO donors increased S-nitrosylation of cell death receptors and overall induction of cell death markers in control and Sorafenib-treated cells. In conclusion, Sorafenib induced alteration of cell death receptor S-nitrosylation status which may have a relevant repercussion on cell death signaling in hepatoblastoma cells. PMID:26233703

  8. Molecular and cellular control of cell death and defense signaling in pepper.

    PubMed

    Choi, Hyong Woo; Hwang, Byung Kook

    2015-01-01

    Pepper (Capsicum annuum L.) provides a good experimental system for studying the molecular and functional genomics underlying the ability of plants to defend themselves against microbial pathogens. Cell death is a genetically programmed response that requires specific host cellular factors. Hypersensitive response (HR) is defined as rapid cell death in response to a pathogen attack. Pepper plants respond to pathogen attacks by activating genetically controlled HR- or disease-associated cell death. HR cell death, specifically in incompatible interactions between pepper and Xanthomonas campestris pv. vesicatoria, is mediated by the molecular genetics and biochemical machinery that underlie pathogen-induced cell death in plants. Gene expression profiles during the HR-like cell death response, virus-induced gene silencing and transient and transgenic overexpression approaches are used to isolate and identify HR- or disease-associated cell death genes in pepper plants. Reactive oxygen species, nitric oxide, cytosolic calcium ion and defense-related hormones such as salicylic acid, jasmonic acid, ethylene and abscisic acid are involved in the execution of pathogen-induced cell death in plants. In this review, we summarize recent molecular and cellular studies of the pepper cell death-mediated defense response, highlighting the signaling events of cell death in disease-resistant pepper plants. Comprehensive knowledge and understanding of the cellular functions of pepper cell death response genes will aid the development of novel practical approaches to enhance disease resistance in pepper, thereby helping to secure the future supply of safe and nutritious pepper plants worldwide.

  9. The mystery of underground death: cell death in roots during ontogeny and in response to environmental factors.

    PubMed

    Bagniewska-Zadworna, A; Arasimowicz-Jelonek, M

    2016-03-01

    Programmed cell death (PCD) is an essential part of the ontogeny of roots and their tolerance/resistance mechanisms, allowing adaptation and growth under adverse conditions. It occurs not only at the cellular and subcellular level, but also at the levels of tissues, organs and even whole plants. This process involves a wide spectrum of mechanisms, from signalling and the expression of specific genes to the degradation of cellular structures. The major goals of this review were to broaden current knowledge about PCD processes in roots, and to identify mechanisms associated with both developmental and stress-associated cell death in roots. Vacuolar cell death, when cell contents are removed by a combination of an autophagy-associated process and the release of hydrolases from a collapsed vacuole, is responsible for programming self-destruction. Regardless of the conditions and factors inducing PCD, its subcellular events usually include the accumulation of autophagosome-like structures, and the formation of massive lytic compartments. In some cases these are followed by the nuclear changes of chromatin condensation and DNA fragmentation. Tonoplast disruption and vacuole implosion occur very rapidly, are irreversible and constitute a definitive step toward cell death in roots. Active cell elimination plays an important role in various biological processes in the life history of plants, leading to controlled cellular death during adaptation to changing environmental conditions, and organ remodelling throughout development and senescence. PMID:26332667

  10. Citreoviridin induces ROS-dependent autophagic cell death in human liver HepG2 cells.

    PubMed

    Liu, Ya-Nan; Wang, Yue-Xia; Liu, Xiao-Fang; Jiang, Li-Ping; Yang, Guang; Sun, Xian-Ce; Geng, Cheng-Yan; Li, Qiu-Juan; Chen, Min; Yao, Xiao-Feng

    2015-03-01

    Citreoviridin (CIT) is one of toxic mycotoxins derived from fungal species in moldy cereals. Whether CIT exerts hepatotoxicity and the precise molecular mechanisms of CIT hepatotoxicity are not completely elucidated. In this study, the inhibitor of autophagosome formation, 3-methyladenine, protected the cells against CIT cytotoxicity, and the autophagy stimulator rapamycin further decreased the cell viability of CIT-treated HepG2 cells. Knockdown of Atg5 with Atg5 siRNA alleviated CIT-induced cell death. These finding suggested the hypothesis that autophagic cell death contributed to CIT-induced cytotoxicity in HepG2 cells. CIT increased the autophagosome number in HepG2 cells observed under a transmission electron microscope, and this effect was confirmed by the elevated LC3-II levels detected through Western blot. Reduction of P62 protein levels and the result of LC3 turnover assay indicated that the accumulation of autophagosomes in the CIT-treated HepG2 cells was due to increased formation rather than impaired degradation. The pretreatment of HepG2 cells with the ROS inhibitor NAC reduced autophagosome formation and reversed the CIT cytotoxicity, indicating that CIT-induced autophagic cell death was ROS-dependent. In summary, ROS-dependent autophagic cell death of HpeG2 cells described in this study may help to elucidate the underlying mechanism of CIT cytotoxicity.

  11. Mitophagy switches cell death from apoptosis to necrosis in NSCLC cells treated with oncolytic measles virus.

    PubMed

    Xia, Mao; Meng, Gang; Jiang, Aiqin; Chen, Aiping; Dahlhaus, Meike; Gonzalez, Patrick; Beltinger, Christian; Wei, Jiwu

    2014-06-15

    Although apoptotic phenomena have been observed in malignant cells infected by measles virus vaccine strain Edmonston B (MV-Edm), the precise oncolytic mechanisms are poorly defined. In this study we found that MV-Edm induced autophagy and sequestosome 1-mediated mitophagy leading to decreased cytochrome c release, which blocked the pro-apoptotic cascade in non-small cell lung cancer cells (NSCLCs). The decrease of apoptosis by mitophagy favored viral replication. Persistent viral replication sustained by autophagy ultimately resulted in necrotic cell death due to ATP depletion. Importantly, when autophagy was impaired in NSCLCs MV-Edm-induced cell death was significantly abrogated despite of increased apoptosis. Taken together, our results define a novel oncolytic mechanism by which mitophagy switches cell death from apoptosis to more efficient necrosis in NSCLCs following MV-Edm infection. This provides a foundation for future improvement of oncolytic virotherapy or antiviral therapy.

  12. Necrosis, and then stress induced necrosis-like cell death, but not apoptosis, should be the preferred cell death mode for chemotherapy: clearance of a few misconceptions

    PubMed Central

    Zhang, Ju; Lou, Xiaomin; Jin, Longyu; Zhou, Rongjia; Liu, Siqi; Xu, Ningzhi; Liao, D. Joshua

    2014-01-01

    Cell death overarches carcinogenesis and is a center of cancer researches, especially therapy studies. There have been many nomenclatures on cell death, but only three cell death modes are genuine, i.e. apoptosis, necrosis and stress-induced cell death (SICD). Like apoptosis, SICD is programmed. Like necrosis, SICD is a pathological event and may trigger regeneration and scar formation. Therefore, SICD has subtypes of stress-induced apoptosis-like cell death (SIaLCD) and stress-induced necrosis-like cell death (SInLCD). Whereas apoptosis removes redundant but healthy cells, SICD removes useful but ill or damaged cells. Many studies on cell death involve cancer tissues that resemble parasites in the host patients, which is a complicated system as it involves immune clearance of the alien cancer cells by the host. Cancer resembles an evolutionarily lower-level organism having a weaker apoptosis potential and poorer DNA repair mechanisms. Hence, targeting apoptosis for cancer therapy, i.e. killing via SIaLCD, will be less efficacious and more toxic. On the other hand, necrosis of cancer cells releases cellular debris and components to stimulate immune function, thus counteracting therapy-caused immune suppression and making necrosis better than SIaLCD for chemo drug development. PMID:25594039

  13. Necrosis, and then stress induced necrosis-like cell death, but not apoptosis, should be the preferred cell death mode for chemotherapy: clearance of a few misconceptions.

    PubMed

    Zhang, Ju; Lou, Xiaomin; Jin, Longyu; Zhou, Rongjia; Liu, Siqi; Xu, Ningzhi; Liao, D Joshua

    2014-01-01

    Cell death overarches carcinogenesis and is a center of cancer researches, especially therapy studies. There have been many nomenclatures on cell death, but only three cell death modes are genuine, i.e. apoptosis, necrosis and stress-induced cell death (SICD). Like apoptosis, SICD is programmed. Like necrosis, SICD is a pathological event and may trigger regeneration and scar formation. Therefore, SICD has subtypes of stress-induced apoptosis-like cell death (SIaLCD) and stress-induced necrosis-like cell death (SInLCD). Whereas apoptosis removes redundant but healthy cells, SICD removes useful but ill or damaged cells. Many studies on cell death involve cancer tissues that resemble parasites in the host patients, which is a complicated system as it involves immune clearance of the alien cancer cells by the host. Cancer resembles an evolutionarily lower-level organism having a weaker apoptosis potential and poorer DNA repair mechanisms. Hence, targeting apoptosis for cancer therapy, i.e. killing via SIaLCD, will be less efficacious and more toxic. On the other hand, necrosis of cancer cells releases cellular debris and components to stimulate immune function, thus counteracting therapy-caused immune suppression and making necrosis better than SIaLCD for chemo drug development. PMID:25594039

  14. Cell death versus cell survival instructed by supramolecular cohesion of nanostructures

    PubMed Central

    Newcomb, Christina J.; Sur, Shantanu; Ortony, Julia H.; Lee, One-Sun; Matson, John B.; Boekhoven, Job; Yu, Jeong Min; Schatz, George C.; Stupp, Samuel I.

    2014-01-01

    Many naturally occurring peptides containing cationic and hydrophobic domains have evolved to interact with mammalian cell membranes and have been incorporated into materials for non-viral gene delivery, cancer therapy, or treatment of microbial infections. Their electrostatic attraction to the negatively charged cell surface and hydrophobic interactions with the membrane lipids enable intracellular delivery or cell lysis. While the effects of hydrophobicity and cationic charge of soluble molecules on the cell membrane are well known, the interactions between materials with these molecular features and cells remain poorly understood. Here we report that varying the cohesive forces within nanofibres of supramolecular materials with nearly identical cationic and hydrophobic structure instruct cell death or cell survival. Weak intermolecular bonds promote cell death through disruption of lipid membranes, while materials reinforced by hydrogen bonds support cell viability. These findings provide new strategies to design biomaterials that interact with the cell membrane. PMID:24531236

  15. KLF4 Is Essential for Induction of Cellular Identity Change and Acinar-to-Ductal Reprogramming during Early Pancreatic Carcinogenesis.

    PubMed

    Wei, Daoyan; Wang, Liang; Yan, Yongmin; Jia, Zhiliang; Gagea, Mihai; Li, Zhiwei; Zuo, Xiangsheng; Kong, Xiangyu; Huang, Suyun; Xie, Keping

    2016-03-14

    Understanding the molecular mechanisms of tumor initiation has significant impact on early cancer detection and intervention. To define the role of KLF4 in pancreatic ductal adenocarcinoma (PDA) initiation, we used molecular biological analyses and mouse models of klf4 gain- and loss-of-function and mutant Kras. KLF4 is upregulated in and required for acinar-to-ductal metaplasia. Klf4 ablation drastically attenuates the formation of pancreatic intraepithelial neoplasia induced by mutant Kras(G12D), whereas upregulation of KLF4 does the opposite. Mutant KRAS and cellular injuries induce KLF4 expression, and ectopic expression of KLF4 in acinar cells reduces acinar lineage- and induces ductal lineage-related marker expression. These results demonstrate that KLF4 induces ductal identity in PanIN initiation and may be a potential target for prevention of PDA initiation.

  16. A Versatile Cell Death Screening Assay Using Dye-Stained Cells and Multivariate Image Analysis

    PubMed Central

    Collins, Tony J.; Ylanko, Jarkko; Geng, Fei

    2015-01-01

    Abstract A novel dye-based method for measuring cell death in image-based screens is presented. Unlike conventional high- and medium-throughput cell